Information Center
Technical InformationCoronado Tech Note – 001: The Central Obstruction Coronado occasionally receives requests for information regarding the central obstruction evident in our AS-1/SolarMax series filters. The mask creating this obstruction is there to prevent direct sunlight from being transmitted to the image plane through a central, uncoated section of the etalon filter component. This region accommodates an extra ‘spacer’ in the construction of the etalon, which is an integral part of the superior performance of an AS-1/SolarMax filter and is the principle on which the filter patents are based. The etalon consists of two flat plates of fused silica, coated with a hard, low-loss dielectric coating specific to the filter’s characteristics. These plates are separated by ‘spacers’ made of extremely low coefficient of expansion materials, which are optically contacted to the plates and which hold the plates at the required separation and parallelism. In the classical air-spaced etalon, these spacers,- usually three in number,- are arranged around the edge of the plates. In the Coronado design, the number of edge spacers is increased according to a formula related to the diameter of the plates and an extra spacer is positioned in the center of the plates. This patented construction leads to a number of advantages in the performance of the etalon and, indeed, allows the etalon to be used as a Solar filter. The central obstruction has two principle effects on the performance,- thermal stability and diffraction. These topics will be discussed separately. ************************* Thermal Stability Traditionally, the air-spaced etalon has been used for its high thermal stability relative to the solid spaced version, which, due to its being constructed of an optical material will always be temperature dependent because of its coefficient of expansion and the thermal coefficient of refractive index. However, in considering this construction for a Solar filter, one has to be very careful to define the thermal stability correctly. For instance, if a classical air-spaced etalon, as described above, has a bandwidth (HBW) and a tuned wavelength (CWL) at temperature T then, if the temperature is raised to T’ the etalon will have the same HBW and CWL ONCE THE ETALON HAS COME INTO THERMAL EQUILIBRIUM AT THE NEW TEMPERATURE. However, it will NOT have the same HBW and CWL during the time that the temperature is changing. This is extremely important when using such an etalon as a Solar filter because, as the filter is facing the Sun during use, the filter is NEVER IN THERMAL EQUILIBRIUM. This has always precluded such etalons from being used as Solar filters except under laboratory conditions. To resolve this problem, Coronado designed and patented a new construction for air-spaced etalons. As mentioned above, this consists of increasing the number of edge spacers and adding an extra spacer in the centre. This design not only improves the ability to manufacture such etalons economically and in quantities, but dramatically improves the thermal stability of them under NON-THERMAL EQUILIBRIUM conditions. For an explanation of this, refer to the following diagrammes 
Fig.1 represents an air-spaced etalon with edge spacers only. Radiation from the Sun is incident on surface 1 (S1) raising the temperature, after a time ‘t’ to T1. (In some cases there will be an Energy Rejection Filter positioned in front of the etalon;- however, due to this component absorbing a high percentage of the incident radiation, the ERF’s temperature will increase and it will become the heat source for the etalon). Due to the poor thermal conductivity of the fused silica, the temperature at S2 is somewhat lower, say, T2. The same argument applies to S3 and S4. Thus, the temperatures at these surfaces at any time ‘t’ are related by: T1 > T2 > T3 > T4 This means that the lateral expansion of the plates is different at each surface (and every plane in between). Because the plates are rigidly held together at the edges by the spacers, this situation results in the shape depicted in Fig.2, which is exaggerated for clarity. As can be seen from the figure, the result is that the air-space between the plates takes on the shape of a meniscus lens instead of the plane parallelism required of the etalon. This causes the central wavelength to change in accordance with the new ‘average’ thickness of the gap and the bandwidth of the etalon to broaden due to the gap no longer being parallel. In Fig.3 can be seen the result of adding a central spacer to an etalon undergoing the same thermal radiation. In this case, as the first etalon plate bends under the influence of the thermal gradient, the central spacer ensures that the second plate bends in the same manner, even though this bending would normally be less under the incident thermal load. The result is that both the thickness of the air-gap and the parallelism of the plates are maintained to a high degree of accuracy. CONCLUSION: BECAUSE A SOLAR FILTER, IN USE, IS NEVER IN THERMAL EQUILIBRIUM, AN AIR-SPACED ETALON FILTER MUST HAVE THE CONSTRUCTION OF THE PATENTED CORONADO DESIGN IN ORDER TO MAINTAIN STABLE CHARACTERISTICS. *********************** Diffraction. The central obstruction in a Coronado filter has the same effect on image quality as that of a Cassegrain type, or Newtonian, telescope. In telescopes of this type, the obstruction, as a fraction of aperture, is generally between 25% and 35% although for some instruments, solely intended for photography, this can be as high as 50%. In the Coronado AS-1 filters, this percentage is between 16% and 24% depending on the model. The effects of the central obstruction are twofold;- a decrease in the amount of light received by the instrument and a modification of the image contrast. The decrease in the amount of light is proportional to the surface area obstruction. In all cases, this is fairly modest: e.g. ~12% for 35% obstruction and ~2.5% for 16% obstruction. For a Solar filter, of course, this loss is a moot point as there are components in the filter to reduce the throughput much more than these values in order to render the resulting image safe to observe. 
Fig.4 
Fig.5 
Fig.6 However, the situation regarding diffraction induced contrast reduction is worth examining further. The size of the obstruction has a direct effect on the Airy disc. This is the pattern produced in the image plane of a point source by a perfect optical system (Fig.4). The effect of the obstruction is to put less light into the central disc of the Airy pattern and to increase the light in the first ring. The effect of this for obstructions of 20% and 33% can be seen in Figs.5 & 6. Although this looks like a considerable difference, it can be seen in the graph of Fig.7, that the extra light in the first ring only changes from 1.7% to 5.4% of the intensity in the central disc. For obstructions of 25% or less, as in the AS-1/SolarMax series filters, this would be completely unnoticeable. 
Fig.7 The effect of the obstruction on contrast can be seen by examining the MTF curve (Fig.8). The Modulated Transfer Function (MTF) is a measure of how perfectly an optical system translates an object into an image. This translation can never be perfect due to the diffraction laws of optics. The MTF can be determined for various spatial frequencies corresponding to the sizes and spacing of details under observation. Fig.8 shows that the contrast is modified in a complex manner. It does, indeed, decrease with an increase in the diameter of the obstruction,- BUT ONLY IN LOW AND MEDIUM FREQUENCIES. On the other hand, in the high frequency range, the contrast is not only maintained, BUT IS ACTUALLY SLIGHTLY INCREASED. 
Fig.8 To examine the effects on the resolution of the system, two cases must be considered: 1) High contrast structures: e.g. Moon, Double Stars, Sun.. Since the resolution limit is on the right of the MTF curve (Fig.8), it is NOT MODIFIED BY THE OBSTRUCTION. 2) Low contrast structures: e.g. planetary surfaces. The resolution is at a lower frequency than above. For details of very low contrast, this limit will be to the left of the intersection of the curves and, in this case, is lowered according to the size of the obstruction. Whether the resolution limit is to the left or right of the intersection of the curves, (and, therefore, whether or not there is a reduction of the resolution),- depends on the intrinsic contrast of the object. This can vary with wavelength and also with the imaging technique. The contrast threshold differs from about 2% for the eye to, perhaps, 0.5% for CCD. Obviously, the above is valid only if the other aberrations of the optical system are sufficiently low. Optical aberrations and lack of proper collimation of the system have far more serious effects on the resolution and contrast than those of the central obstruction in the sizes being considered. CONCLUSION: BECAUSE OF THE HIGH CONTRAST NATURE OF SOLAR OBSERVATION, THE CENTRAL OBSTRUCTION OF THE AS-1/SOLARMAX SERIES FILTERS HAS NO NOTICEABLE EFFECT ON CONTRAST AND, WHEN USED IN CONJUNCTION WITH SUPERB OPTICS, AS WITH THE MAXSCOPE TELESCOPES MAY EVEN INCREASE THE RESOLUTION OF THE INSTRUMENT. Acknowledgements: Computer generated figures and graphs are used courtesy of Thierry Legault. LIGHT FROM THE SUN Light from the Sun has a unique 'signature' imposed upon it from the various elements which make up its composition. This becomes visible by stretching the light out into a spectrum. Superimposed on the spectrum will be seen many dark lines or 'absorption' lines where the continuous illumination, from deep red to violet, has been filtered out by the action of these elements, at different levels of the Sun' structure, as the light proceeds outwards and on into space. If one uses an instrument which allows observing the Sun at one of these lines, the solar disc will be observed in only the element that produced that particular line.
The Fabry-Perot Etalon-Filter......
Coronado reserves the right to change specifications witout prior notice.
The Importance of Angles...
Filter ModelsWe have chosen a number of filter configurations from our many development programmes for the amateur community which provide a range of performance, cost and system compatibility. Together, they provide ideal choices for everyone from the serious Solar astronomer to the casual observer.
AS1 Series
SMn Series
Special Purpose FiltersSince our development of the basic ultra-narrowband filter over thirty years ago, we have developed many variations for special, scientific programmes. Most of these designs are available on custom order,- including filters that accept larger fields, thermally stable high index filters, tunable filters and filters for wavelength ranges from the Ultra-Violet to the Infra-Red. In addition, accessory optics can be provided to match these filters to your instrument.
TECHNICAL MEMOEtalons are fixed spacing, Fabry-Perot interferometers. They are used for spectral analysis, laser mode selection and monitoring and, when tuned to a specific wavelength, very narrowband optical filters.
Technical Considerations. The transmittance of a Fabry-Perot is given by the following
T = t?/(1-Rs)? (1+(4Rs/(1-Rs )?))sin?D.........................(1) where: t = the transmittance of each plate assuming they are equal, and there is no phase change upon reflection. D = (2  ndcos )/l........................................................(2)
where: n = the refractive index of the spacer between the reflective coatings and the physical thickness of the spacer and the angle
of incidence within the Fabry Perot. Now, to simplify, let: F = 4Rs/(1-Rs)? Then: T = t?/(1-Rs)? (1+Fsin?D) Under ideal circumstances there is no measurable absorption in the coatings and then: t = 1 - Rs and, T = 1/(1+Fsin?D)..........................................................(3)
0.5 = 1/(1+FD?) The separation of successive fringes being , then:
FSR/2D = F0.5/2 = Finesse
i.e.: Finesse = Rs0.5/(1 - Rs).............................................(4)
This is referred to as the reflective Finesse and is a critical specification of the Fabry Perot etalon, giving the resolution of the transmission band as a function of the Free Spectral Range or the order between fringes. The latter is a measure of the etalon’s ability to distinguish between features.
As can be seen the reflective Finesse is solely dependent on the value ‘R’ of the reflectance of each of the plates comprising the etalon. Some typical values of this are as follows:
In order to define the true performance of the etalon, one must also take into account what is referred to as the Defect Finesse. This is a measure of the degree to which the fabrication of the etalon approaches the theoretical value required to achieve the reflective Finesse. It is defined as:
Coatings : One of the most critical aspects of Fabry-Perot construction is the quality of the coatings. Even very small absorption and scatter losses will have a drastic effect on the performance of the etalon,- particularly on its throughput. In addition, many coating materials, deposited by standard techniques, exhibit a growth structure which increases the roughness of the surface in proportion to the thickness of the coating. This is not serious for solid etalons because the ‘cavity’ is formed by the coating in direct contact with the etalon spacer. For air-spaced designs, however, this can be a serious cause of poor performance. Another coating defect, which does affect the solid design more than the air-spaced, is phase dispersion across and between the two coatings. This alters the effective finesse across the etalon and creates a residual transmission loss if it occurs between coatings. The reason this affects solid etalons more is that the coatings are applied in two coating ‘runs’ and, therefore, may have slight differences between them. Finally, in many etalon applications involving lasers, the fluence damage threshold has to be sufficiently high that the coatings are not damaged. Etalons are particularly prone to this type of damage due to their having,- like a laser,- a cavity, in which the total flux is considerably higher than that transmitted. In addition, for some laser applications,- e.g. excimer lasers,- the etalon coatings have to withstand a potentially caustic environment.
Tuning and Stability :
The ‘inverse’ of an etalon’s tunability is its stability. The air-spaced designs are the most thermally stable. In addition, however, Coronado has a proprietary design to significantly increase this stability. In this ‘Balanced Alpha” design, use is made of spacer materials of both positive and negative coefficients of thermal expansion, assembled in such a way that the already extremely low individual values cancel out, resulting in an etalon having a thermal stability of <1 part in 10 Another ‘inverse’ of the angle tunability of an etalon is its angular acceptance. Theoretically, of course, to achieve the designed Finesse, the incident radiation has to be highly collimated. However, for particular applications as ultra narrowband filters, there is a tolerance on this collimation dependent on the usable transmission and bandpass tolerances. As the angular effect is a function of the spacer refractive index, this angular acceptance of the filter can be increased by using higher refractive index spacers. CIG can manufacture etalon filters in a wide range of materials and have specific designs in which this effect is maximised. Coronado Tech Note 002 The Fabry-Perot Etalon Filter TECH NOTE 002 THE FABRY-PEROT ETALON FILTER The Fabry-Perot etalon consists of two, semi-reflective surfaces, separated by a gap. This can be facing surfaces of two substrates separated by air or vacuum or the two sides of a solid substrate. Given sufficiently high optical tolerances, this structure has the unusual property of reflecting all wavelengths except those which are an integral number of half waves of the gap between the surfaces. These wavelengths it transmits fully. As such it can be used, very effectively, as a filter. In order to look at the properties of the etalon as a filter, it is convenient to examine the general equation that defines the interference,- viz: Te = T2 / (1 – R)2 {1 + [4R/(1 – R)2]sin2d} ...................................(1) in which: Te is the total transmission of the etalon. T is the transmittance of the coating on either surface. R is the reflectance of the coating on either surface. d is the angle of incidence of the light within the etalon cavity. This can be simplified because of the following relationships: It can be assumed that, with good coatings, T = 1 – R and, further, let: F = 4R/(1 – R)2 Then, (1) becomes: Te = 1 / 1 + Fsin2d...................................................................(2) Now, Te is a maximum for d = mp where m is the order of intereference and is: 0, +/-1, +/-2, etc. Also, the Finesse (F) of the etalon is defined as: F = FSR / HBW Where FSR is the Free Spectral Range of the etalon;- i.e. the distance between adjacent peaks of transmission and HBW is the bandwidth of the etalon at 50% of the peak transmission; i.e.: HBW = 0.5Te Therefore, from (2): 0.5 = 1 / 1 + Fsin2d For a narrowband filter sind = d Therefore, 0.5 = 1 / 1 + Fd2 i.e.: d = 1 / F0.5 (= ½ Fringe, or filter, width) The separation between fringes is p, therefore, Finesse (F) = pF0.5 / 2 Or, F = pR0.5 / (1 – R) ………………………………..(3) This is a very significant result as it indicates that the Finesse of an etalon is totally dependent on the reflectance of the surfaces only. However, hidden in this calculation is the presumption that the etalon plates, or surfaces, are perfectly flat and parallel,- a condition that would not exist in practice. To ascertain how non-perfection in these parameters affects the performance of the filter, an error will be added to the design to see how this affects the actual Finesse. Let the error in the etalon be Dd And let this be Then: Dl / l = Dd / d = Where: Dl is error in wavelength, and Dlh is half the bandwidth Now, since the resolving power of the filter is defined as: l / Dl = mF Then, F This is a most important equation in the construction of an etalon filter as it defines the optical quality of the substrates in order to achieve a particular Finesse. The Finesse is very important to the overall design of a system as it connects the bandwidth with the Free Spectral Range. The longer the FSR, the easier it becomes to use other filters to block unwanted orders and wavelengths. However, a longer FSR implies a wider bandwidth for a given Finesse. It can be seen from (4) that for a Finesse of 25, which is typically required to construct a complete system, the required optical tolerance is 0.01l. This is a total allowable tolerance between the flatness of the surfaces and the parallelism of the surfaces. Therefore, statistically, each of these has to be However, it is very important to note that the beginning of this calculation made the assumption that Dd | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CUSTOMER FEEDBACKJuly 1 2004 > Message : I have just finshed using my PST for the first time today and even though I didn't have it in time for the Venus transit, it was well worth the wait. I feel I got a quality product at an unbelieveable low price from a company that wasn't going to bow to pressure to meet a deadline, but was going to make the best product possible. > Thanks, Allan June 29 2004 BBC Transit of Venus Coverage from EGYPT Hi Gerry, Just a quick note to follow up on our previous correspondence and to thank you again for your invaluable advise. By introducing John Adair to me, the production process was made so much easier. John's enthusiasm and expertise was just what was required and he threw himself into the technical preparation for the shoot with such vigour that all I had to do was stand back and watch in admiration. John's mount was programmed to follow the Sun, so tracking Venus required John to continually make tiny adjustments to the mount, which he did for the entire transit without a single break. An incredible effort of concentration that I doubt anyone other than John would have had the motivation to complete. Also his single minded determination to get the best possible picture matched with the high quality of your filters (<0.5A SM90)gave us a image of such clarity that the our programme acquired a gloss that other parts of the media were unable to match. Furthermore, the Coronado hats that you sent John were used by the crew and I don't think that they would have survived without them for the 8 hours we spent on that hot flat roof! I hope that the other broadcasts that you were involved with had similar success. With best wishes, Mark Bridge. June 25th. 2004 Dear Sir or Ma'am, My PST arrived (in perfect condition) a few days ago. All I can say is WOW!!!! GREAT SCOPE!!! What fantastic views. This is my first foray into Ha observing and couldn't be more pleased. The prominences were awesome and the surface detail was better than I expected. Thank you. Steve Biondo June: 14 2004 With reference to questions re temperature stability: By the 8th June everything was working superbly. We started tracking the Sun two hours before transit and finished about 4 hours after transit. The image from the 90mm Filter and BF30 didn’t miss a beat the whole time and I didn’t need to adjust anything. Now that was a test if there ever was one, well done Coronado. Although the mount was electronically tracking the Sun I had to track Venus manually as it moved across the Sun, for six hours non stop. That was the new requirement from the production company. Although temperatures were around 46deg John Adair Gerry...just thought you would like to know your little prototype NearStar (serial 177) that you sold me during the summer of 2000 did a commendable job today during the Venus crossing here in Abu Dhabi, United Arab Emirates. As you may recall the prototype did not have a > filter tilting mechanism...but 42 deg/c and it stayed on band for the 6 hours of the crossing. > Managed to make a small movie of the event with the NearStar...once I process it, I'll try to send you a copy....it's about 6MB, any file transfer > limits with your Internet Provider? > > David Grassbaugh - UAE > (Formerly Cairo, Egypt) > Saturday, July 12, 2003 Hi Gerry!I have been putting the ole SM90 through its paces and all I can say is"WOW"!! The more one views, the more detail that is revealed. I am making arrangements to attend your Hands On The Sun in October with a friend...I can only imagine what that experience would be like! I have been introducing others to H-alpha solar viewing and the responsehas been incredulous. I will be setting up the SM90 outfit for a group of teachers at Washington University in St. Louis on Tuesday. I can't wait to see their response!Thank you for such an excellent product! -Steve Sands "Thanks Nick, for the good service, as usual. You really stayed on top of things. I appreciate it. -Tony Clarke Hi Rickie/Nick/Bill: After looking through my newly acquired Maxscope 60 for the first time, I am not only in love with my new H-Alpha scope, but with your company as well. BTW, do you sell any "Coronado" merchandise, i.e.: caps, mugs, tee-shirts? I'm feeling the whole Coronado mojo thing. Please tell Mr. Lunt, that he's dethroned Santa Claus as my favorite "white bearded guy" and please thank him for making such a wonderful product. Regards, -Tom (soon to be double stacked) Ruggiero August 6 I received my SolarMax60 today. Better than new. Thanks again for the outstanding service/support- you guys are great! -Craig July 14 Keep up the good work. You folks have set the Solar observing world on fire! Sincerely, -Tom June 11 2002 we just bought a ASM40/BF30 (a model no longer in production) combination of Wolfgang Lille (Germany) mounted behind a telecentric system made by him. The first images are marvellous. Vanbeselaere Johan ACG vzw Ieper Belgium May 28th. Message : Hi Folks I received the SolarMax 40mm filter a couple of days ago and I've gained a little experience with observing the sun in H-alpha. Thank you for the quality and craftsmanship of the filter -- the optics and machine work exceeded my expectations! First, a few comments concerning the SolarMax. I'm guessing you guys are working overtime to keep us customers happy and, I for one, will let you know yours efforts are appreciated. I was a bit concerned about the small aperture of the SolarMax. I (mistakenly) assumed a dim image (the Pronto would be working as a f/12 system) and being restricted to low power views plus (relatively) low resolution. I shouldn't have worried! In use, the solar disc is almost too bright -- the filaments and other disc details are more readily visible when a thin haze reduces the brillance of the solar disc. Perhaps a neutral density filter will help when the sky is transparent. The prominences show good contrast and display fascinating detail. My first encounter with the Coronado filters came at the 2001 WinterStar Party where, if I recall correctly, the 60 mm and 90 mm filters were demonstrated. As I remember, the daytime seeing conditions at Camp Wesumkee were outstanding and I shouldn't expect conditions to be as cooperative in the real world -- my front yard. How would a 40 mm filter compare? I managed to convince myself I would see inferior images of the H-alpha disc..again a bad move. I'm delighted with the filter's performance! Using a 5 mm Radian eyepiece with the Pronto -- that's ~ 97X or ~60X per inch of aperture! --I was astonished to see small surge prominences form and decay in a matter of minutes. Secchi's burning prairies -- the spicules -- began to resolve and gave the solar limb a ragged appearance. I estimate the resolution of the optics at ~ 4-5 arc seconds when the air is steady -- typically early morning from my location. Am I pleased? Yes! I can now follow my amateur astronomy hobby without regard to the phase of the moon or loss of sleep!Thanks again for a fine product! -Dave Riddle May 2 My 90mm filter arrived yesterday - how nice of you to time it to arrive on my birthday! On the happy side - I had a moment to view the sun this morning, between clouds. The fit on the Traveler is excellent and the first views were truly exceptional. Very bright and wonderful contrast. I was mesmerized by the low power view - 43X - which just removed the ghost image from the field of view and provided a great balance of surface and prominence detail. Got into work at noon. Will save higher power testing to the weekend - the weather is supposed to be clear and warm all day tomorrow. I could see how one could mistake the outlying solar disk reflections for the true image - even though I was prepared for them after reading your solar chat - they are quite sharp and I think one is not prepared for how bright the true image will be. Might be worth a mention in your set-up literature that accompanies the filter. Thanks for an extraordinary filter. I will be at NEAF and will stop by to say hello. -A.F. New York April 19 We got the Nearstar this morning, and a small gap in the clouds, and some sunspots. WOW!*!*! Ta. Di and John, England April 14 The Solar Max(60) is great and I find myself using it daily at home to keep track of the changing Sun. Sincerely, -R. Thomas, CA April 12 To let you know how I use the Solarmax 40, I take my TV85 around with me on weekends. Yesterday, I was with my youngest daughter at a volleyball tournament all day. About 1515 PDT, the clouds cleared enough such that the sun was strongly visible. I set up the TV85 and Solarmax to enjoy the view.All of her teammates wanted to know what I was doing, and I explained. So all of the kids and their parents lined up. The tournament was at a local junior college. Campus security and other persons on campus soon joined the line. Everyone was amazed at the view.I intend to share the view this weekend (weather permitting) at the Orange County (California)Science Fair. -J.B. ,Ca First Light for Jack Eastman - (To)All...it finally happened, my Coronado SolarMax arrived Thursday, April 11, in perfect condition. The adaptor plate arrived a couple of weeks earlier, and fit like a glove on my old 60mm Polarex (Unitron) which was my second ever telescope, and now rides alongside my 12-cm refractor. The 12-cm has a Herschel Wedge filter, so I can now observe simultaneously in Ha and "white" light. Friday dawned with a fairly thick layer of Cirrus clouds, these, I figured, would ruin any views of prominences and the like due to a large amount of scatter and subsequent loss of contrast. At least I could check that everything fit properly and the diagonal with the blocking filter would focus properly. I set everything up and was amazed at the view. The chromosphere was obvious as could be, and there was a huge prominence on the East limb, poking out about 0.1 of the Sun's radius and was at least half again as wide. As I moved around the limb, there were numerous other prominences, all quite spectacular. And this was strained through a fairly thick Cirrus clouds. As I was marveling over the view a sunspot group near the West side of the disk lit up, became very bright and a line of light, looking much like a river of brightly glowing, molten metal appeared down the length of the sunspot group. Clearly a major flare, or so I thought, my total Ha observing experience now approaching 20 minutes or so. The flare occurred about 10:20 or so MST and the whole show was over in about 15 minutes.Later, under better skies, the big prominence on the East limb showed an amazing amount of structure as did the other smaller prominences. For the rest of the weekend I did see another couple of small flares,one produced a very rapid, pencil thin prominence which literally shot out of the sun, not far from the big prominence mentioned earlier. The little bright spike attained a height of maybe 0.1 solar radius, before it faded out.The large prominence seemed much higher and had several bright spots 0.12 of the Sun's radius.The whole event, from that spike first becoming visible to its disappearance took maybe 6 or 8 minutes. The big prominence was still visible late Sunday as the Sun set behind a bunch of trees. All in all I found the experience fascinating, having never made Ha observations over any length of time. OK, this all sounds like the excitement of a kid with a new toy. Almost,I probably don't qualify as a kid, but the new toy is a blast! And to you at Coronado--- Thanks! See you all at RTMC. Jan. 4 2002 Back at my desk after the Holidays, Just wanted to let you know that the Nearstar arrived OK on 12/19. After several viewings with it, I am totally satisfied with this wonderful creation you have made! Having used some solar H-Alpha filters in the past, it was easy to step back into using one and many of the features I used to see were there. The big surprise was the contrast of the Nearstar, and how I was now able to see some rominences that were "detached" from the edge of the sun or appearing as so. I found it very much necessary to look over the area around the disk some one-third a solar radius away from the edge as there were details here I had not seen before in other equipment. Another new view was seeing greater detail in prominences against the disk (projections the name?) and a almost 3D quality in those that were fairly near the limb. Well done! Lots of fellow viewers impressed also. Wishing all a Happy New Year Russ Chmela , Phoenix Dec. 28th. The Solarmax (40) on my Pronto is just wild! Bob Strong Dec. 24th. I appreciate the excellent service you provide. David B. UK Dec. 26th. received following repair of a Helios: We have had the Helios back about a week and been enjoying it very much. Actually, it is WONDERFUL. Much improved and giving wonderful views. We use a 7mm Nagler eyepiece and Lumicon mirror diagonal. Both Helen and I want to thank you very much for the service and help you have given us and look forward to seeing you again at RTMC. Cordially, Doug Millar and Helen Mahoney Dec. 5 Some people just cannot contain their enthusiasm! WOW! YIKES! CHEEZE! HUBBA, HUBBA! Many , many thanks for a truly superb product. I have it on my 60mm Pentax refractor and it's just wonderful. Ken Whayman, UK, on his SolarMax. What happened to British reserve? Nov. 16 > Message : pleasure doing business with a company that does what they say they will do .I love my SolarMax it provides some stunning views. Thank you all for your excellent customer service. If any future coustmers have any doubts about your product, feel free to give them my e-mail address you're 5 star rated with me. swooden@mo-net.com Nov. 14 > Message : First Light! > > Okay... alright..... I got my SolarMax on Monday... it rained.... Today I packed my Orion ST80 and my SolarMax up in my car this morning and prayed for sunshine.11:30 lunchtime came and out to my car I went to setup my system. Not a cloud in the sky, and WOW what a view!! In 1/2 hour, I saw a huge flare change shape, and another completly disappear. I now know how I am going to be spending my lunchtimes..... solar observing! > This was worth the wait! > Clear skies! > Tim Robertson, CA Oct. 25 I just want to say although the delays and wait were long...the result was VERY MUCH worth the wait and cost. I can't think of very many items I have purchased that have delivered what was "advertised". Of the very few ( the I3 eyepiece, Televue Bino Viewer etc my astronomy colleagues know me as the "Gadget Man"); I would have to say the Solar Max and my ST80 combo are at the top of the list. Kudos to Coronado, Inc and their team. -rang (SDAA-San Diego Astronomy Assoc.) Roy Ang, USA Oct. 9th. I received my SolarMax today. Outstanding, beyond words. Compared it to the "other" Solar filter on my 5" and it's just outstanding. I'm going to enjoy SolarMax for years to come and I'm certainly going to enjoy many, many wondeful days observing the Sun through it. Thank you Nick for outstanding customer service. Dominic Morelli, N.Y. Oct. 2 Message : I received my T-MAX TUNER on Monday. Of course it was raining all day. Today(Tuesday) I set up my SolarMax mounted to a Megrez 80 and the T-MAX TUNER. What a great accessory. I am now able to tune the filter for astonishing detail of prominences as they fly off the sun. To me this is a must have item. The only thing that might be improved on the Tuner is the adjustment knob. When the lever gets pushed up against the housing, it is difficult to move it if you don't have long fingernails. Either a longer lever or a knurled knob might work better. Thank You for making H-Alpha affordable to all of us. Bill Falcone Oct. 1 Gerry -- I left work early Friday to grab the 2 hours of sunlight available given all the rain here...the view through the SolarMax was truly incredible...tremendous surface detail and lots of prominances on the limb. I'm working my way through Harvard Press' new book on the sun to begin to understand everything that has become visible! A good example are the spicules (sp?) on the limb that at first I thought were just limitations of seeing and resolution. I'm beginning to be aware that the SolarMax is revealing fundamental aspects of solar behavior that until very recently were only topics of professional research...I now need to be more careful in challenging myself to think carefully about what I'm seeing...lots of fun! Thanks again for a truely life-enhancing product... Charlie Sept. 6 "I just received my SolarMax and all I can say is WOW! My first view was nothing short of fantastic - massive looping prominences, white solar flares on the solar surface, and long black filaments. I was stunned by the clarity and brightness of these features. Thanks for a great product. it was worth the wait!" - Glen Knight, Boise, Idaho Sept. 5 Gerry Hogan: I've been meaning to post a note giving you first impressions of the NearStar (Helios Generation 2) H-Alpha telescope that I picked up from you in August. I think this product is the closest thing to a fool proof public viewing device that is manufactured by anyone to date. I've had small groups from the Maadi Community Center looking through various eyepieces and EVERYONE was able to see Prominences, Filaments, Flares and Granulation the moment they looked. With the dirty air here in Cairo, Egypt the best full disk views came from a 12.4mm pl. eyepiece. All the features mentioned above were clearly visible. With a 2.5mm Televue Powermate added to the 12.4mm pl. gas streamers were clearly visible in all Prominences viewed. Image brightness with this configuration was somewhat dim, however, when we used a photographer's camera cloak over the eyepiece and head, image contrast and detail was stunning. Maximum magnification in Cairo, was limited to about a 3.5mm eyepiece (ca. 115x) Mechanically the NearStar is well made and the filter is incredibly temperature stable. (even at 107 deg/f) I was initially disappointed with the loss of a filter tilting ring from the Helios to NearStar model. However, after taking a few CCD images with the NearStar, the benefit of having an onband image always in dead center outweighed the luxury (or need) of being able tweak the filter angle. The focuser mechanism initally had quite a bit of shift, but this improved significantly as the unit was broken in with use. Last comment...ship the production units with a main objective lens cap....I will keep the sandwich bag to use as a backup. ;-) Later this month the Cairo American College high school students will put the unit through its paces...I will send some pictures and their comments after this event. David Grassbaugh, Cairo Sept. 5 Wow! What an Awesome review! It is an amazing filter, I knew it the first time I laid my eyes on it. I hope you get to show others in a local astronomy club or neighbors so they can be amazed too. I hope you enjoy it everyday and if you get any photo's or digital images, I would love to see them! Clear Skies, Mike Fowler www.optcorp.com opt@optcorp.com Manager 1-800-483-6287 1-760-722-3343 Oceanside Photo & Telescope 1-760-722-8133 1024 Mission Ave., Oceanside CA. 92054 USA -----Original Message----- From: crosin@socal.rr.com [mailto:crosin@socal.rr.com] Sent: Wednesday, September 05, 2001 12:42 PM To: opt@optcorp.com Subject: Coronado "SOLARMAX" Solar Filter September 5, 2001 Christopher Rosin OPT 1024 Mission Ave. Oceanside, CA 92054 Dear OPT Team, I just wanted to "thank you" for distributing the Coronado SOLARMAX, 40 mm H alpha (<0.8A bandwidth) solar filter. Wow! It was well worth the wait.You guys have been so polite in putting up with my insistent demand for getting this filter ASAP. I vowed to love the sun at RTMC/Riverside,CA,when I first saw this filter demonstrated there. The lady and gentleman representing Coronado said to see you guys at your OPT booth.I got over there as quickly as I could and put my name down with John Downs. Since then I think I've talked to most of you, Craig, Mike, and you other cool:)guys. I've seen faculae that I've only dreamed about and prominences to remember. Yesterday I saw a mushroom flare that I could not take my eye off of for the entire afternoon. I have not seen this type of beauty and clarity before on even very expensive instruments, such as the one at Griffith Park Observatory. You guys are great in taking on and distributing such a fantastic product. Keep up the good work and also thanks to the brilliant engineering team at Coronado. Daytime viewing isn't just for the birds anymore! Keep looking up and catch some awesome rays... Regards, -Christopher Rosin Sept. 4 I have just received your solarmax and is an awesome filter. Ted Wu, Tucson I just received my SolarMax filter and tried it out. Two comments...1. WOW! The view is superb. Glen Knight (Glen's second comment referred to the fact that he has an "old" ST 80 and had difficulty with the adaptor plate.) Sept. 2 Hi Gerry, We were lucky to have sunny moments during the meeting of the amateur solar watchers from northern Belgium in the public observatory of MIRA. I had the opportunity to put a Vixen 102M (f=1000mm) refractor with the Solarmax on their equatorial mount. The quality of the image (in combination with a 40mm or a 30mm eyepiece) impressed everybody and soon the solar viewing with the Solarmax became the main attraction for the public (16 solarwatchers and another 20 people present that day).I'm looking forward to receive the other 2 pieces since they're already sold now. Best regards, Hugo. August 23 Believe me, I AM focussing on the Sun. I am here with three telescopes + mounts + two metal cases of equipment to be used for all sorts of astronomical observation/photography/ videoing, but I am on the point of packing everything back because the ONLY thing I have been using so far is the SolarMax on the Tak FS-60c on a Manfrotto/Bogen tripod and a geared head 410. The whole thing coupled with the Tak Extender-Q and a Zeiss Abbe 16mm (36x). Absolutely amazing. The whole set-up is some 5kg that you can lift with one hand and carry your private solar observatory wherever you want...Amazing. I have been also blessed with a couple of solar explosion. A very beautiful one the day before yesterday (Aug. 21) around Noon. The Sun looked for few minutes like a "Q" Thank you again for the SolarMax! Max Lattanzi (vacationing in Italy) August 20 The William Yang 80mm adapter for the Coronado ASP-60 and BF-30 arrived by FedEx Saturday and here it is as of Saturday afternoon piggybacked on my old workhorse Meade. With an 8.8 Meade super wide in the William and a 50mm Plossl in the Meade covered by a Tuthill Solar Skreen we can have white light and H-alpha at nearly the same scale. Full disks and full flat fields. The Coronado filter is wonderfully bright and the detail is superb. David Roemer Thanks, the spot cleaned up easily with the Lens Pen. No doubt it was a drop of sweat from all the hard work everyone at Coronado is putting into these fine filters! First light was at Stellafane over the weekend. A line immediately formed at the scope so I did not have a lot of time to use it before the clouds rolled in. The first glimpses I did get were wonderful and I can't wait for the next clear day to really put it through it's paces. Michael Virsinger Thank you for sending the SolarMax in time for Stellafane. It arrived at noon on Wednesday. I did as I said I would, that is show the sun to all who came by for a look. Unfortunately it was clear only on Saturday from about 4:00 pm until sundown. During that span about 40-50 people had a look, many of them expressing their thrill at the good views. G. Dyck August 17 I recently received one of the 60mm Solarmax. I was able to use it today for a very short while before high clouds rolled in. All I can say is What took me so long to get one of these. R. Ficara August 17 Thanks for a wonderful product. This little filter (SolarMax) is amazing! Jeff Gardner August 17 VOILA! I couldn't believe the view!!! ...I saw many prominences including a loop and a detached section with subtle details I never imagined I would be able to see. Surface detail included tons of features around what looked like a dark spot. When I looked through a white-light filter, that spot was visible as the largest sunspot in view. I couldn't be more pleased with the performance of your filter!!!This was hands down the BEST view I've ever had- even better than through the setups you brought to Riverside. Which is more than I could have hoped for, because those views were pretty sweet. Craig Anderson on First Light through his Coronado 60 MM filter. Unsolicited review of SolarMax can be found at www.cloudynights.com click on accessories. August 14 received my SolarMax & plate. The H- alpha views were far greater than I expected. I am very pleased and can't wait to use it up at Starfest. I'm sure it will generate alot of curiosity. Thanks to Coronado. I know things have been crazy for you folks. Jeff Gardner August 3 The SolarMax is wonderful- I just wish the seeing were so good. I'm stuck with onshore flow and a cat recovering from surgery so I can't travel inland to enjoy the views much. So far though the views are just fantastic! You'll be hearing from me as I get more time to enjoy I'm sure but let me congratulate you on a fantastic gift to the all the beer-drinking solar observers who were saving for champagne views. Mind-boggling stuff this! Bill Dean Received July 25th. Hi Gerry, Just thought you might like to know that I received my solarmax today. Well luck was with me and it is clear out. First time I looked through it it seemed awfully dim and well *boring*. Little detail and I could just make out a prominence. Well, i was somewhat surprised, but then i thought that i had only looked through $4000 ones before and this was only $900. OK I thought. Well my wife knocked the tripod out of place and I had to recentre the scope. This time i picked up the *real* one. The other must have been one of those secondary ones of something. This one had alot more detail both surface and edges, the prominence was stunning and I felt very happy. I have just come back in to tell you thanks for producing such a first class instrument, especially at a price most amateurs can afford. Forever thankful.. Ben July 7th. Well, just this afternoon I got my first look through a Coronado filter (60mm aperture) at the sun at Stellar, a local telescope shop Vision. I was blown away. What a nice filter and for under $1K. I was heartily impressed. The detail on the disk was crisp and good contrast, including a small flare we saw. There were detached prominences,fountain prominences and a hedgrow all visible, and encyclopedia of forms at one time. Rik Hill Richard E. Hill * * ALPO Web Manager * * Coordinator-ALPO Solar Section * * ALPO Board Member * * http://www.lpl.arizona.edu/~rhill June 27th.. I would like to thank you and all the people at Coronado for answering 2 years worth of dumb questions. The lack of patient providers and quality prompt advice - like the ones received from yor company - I am sure has limited and in some cases excluded many potential amateur astronomers from this wonderful hobby. For what it is worth, all things beeing very similar,the service provided by Coronado was the determinant factor in choosing your products over other providers. Thanx, MAX June 24th. Looking forward to receiving the SolarMax and wishing your company success for all the pioneering efforts you make.J.Drapell Recv. June 21: "This time last year we had no astronomy program at the school. Now we have 12 telescopes, 2 Coronado H alpha Solar filters and 700 budding observers!Our Coronado filters are outside and in use whenever the Sun shines. I invite teachers contemplating an astronomy unit, particularly Solar, to get in touch with me. I'd be happy to discuss our program". Daniel Poccia, Iona Prep. School, New Rochelle, USA tel: 914-632-0714 e-mail drp79@ionaprep.org Recv: June 18th.:Thanks to Coronado, I feel that I've really got back into astronomy. Living in the city the light pollution limits me to moon and planets...this Solar is so easy...there is no excuse for not observing. I get the Helios out before work and on breaks...no time, no effort." M. Kentriakas, NY May 23 Many of my students saw themselves on your web page and were very excited Also, thank you for the Helios 1. It's a great instrument. I plan to use it again next school year to give our youngsters the opportunity to observe the Sun. It's not the same reading about the Sun in a textbook than it is seeing it in real time through an excellent telescope. Regards,Daniel del Valle, Puerto Rico I'm so impressed. Almost embarrassingly so. The H alpha (AS190 on a SKY90) was tested again with more manipulation time and we are beside ourselves as to how beautiful it is. The camera plays a major role in the process. Cameras are far less sophisticated than our eyes, so there is a lot of manipulation to show the various characteristics available with the filter. By increasing gain on the camera, solar flares show up well. By reducing the gain and using the tilting feature on the blocking filter we can see the surface detail very clearly. With the right conditions in Africa, we will be able to display these wonderful visual characteristics to everyone. My best, Larry. (Larry Kenworthy of Magenetic Images Video.com is part of a professional video crew heading for Africa to capture the eclipse for network feed and the Exploratorium. he is using an AS190/BF30 on a Tak Sky90 loaned to us by Texas Nautical Repair.) Recv. April 15: I've just had a look at the image with the ETX70 and the SolarMax, what an incredible picture. P.Y. USA Recv. March 22 Recently I purchased an AS1-90 + BF30 Ha filter from Markus Ludes, Germany. I am quite satisfied by the results I have. H-a views are simply spectacular. V.D. Ukraine Recv. March 16 I received my Helios I this morning. It was picked up in Great Britain yesterday and at 10:00AM it was at my door here in Grayson, Georgia USA. Great service! B.C. Georgia (Customer ordered by phone on March 9, through the Tucson office. In placing the order the customer commented that he was convinced that if he got a Solar filter it would break the drought in Georgia. See message below received march 20th.) Since the Helios I was delivered last Friday we have had over 2 inches of rain! Thanks, Bill Cherepy Grayson, GA I always heard about Coronado's customer-care (and next customer-care), but now I have to notice that it's not very common to have the feeling of even CHATTING with a firm. Thanks for your instant reply, ...you are much better than a cup of instant coffee. D.C. Italy Recv. March 14th. Hello, The filter arrived yesterday. Thank you for the very quick delivery. Best regards, A. B. Belgium Recv. March 5: Thank you for your prompt responses to my queries, this level of customer service has become more rare than the solar eclipses I want to image! B.H. USA At WSP: "This is the best view I have ever had of the Sun in H alpha to date"...Al nagler, Tele Vue. On looking through a TV102 with Coronado 90 mm Solar filter. Recv.March 2:Fantastic turn around time! I can't tell you how much I appreciate the rapid and courteous service you have given to me. A 3 day delivery time is almost unheard of!I must say, this unit is built like a tank, and I'm wonderfully overwhelmed by the quality of scope. Even if it didn't work, I'd be ecstatic!! Now, I'll wait for a clear day...R.B. Michigan Recv. Feb. 21 Im a very big daystar fan, have owned two so far, a .5 and .6 ATM. I like to try new things, and have been looking at your products for a while now. Ive e mailed you before, and you certainly have one thing daystar doesnt anyways, customer support. Not even a customer yet, but get help. T.G. USA Recv. Feb 25. My Gemini 2.5 performs beyond all my expectations. G.W. UK (The customer is referring to the original 40mm filter which is to be reintroduced in early summer.) Recv. Feb. 24 The adapter arrived today! It's beautiful, and is just what I'd hoped for. Hats off to another Coronado success!F.E. CA > Posted Jan. 25th." The Helios 1 is also an ideal educational telescope, whether for an amateur society or a University depeartment. ...For a Solar observer, this telescope is a dream come true." Pam Spence Equipment Review: P 77, February 2001 Astronomy Now. A Ray Of Sunshine "From the first moment I looked through the filter (Coronado AS1-90/BF 30) I was hooked, but when I rotated the filter and fine-tuned the frequency, I was totally mesmerized." Jack Newton writing in the Spring 2001 issue of Amateur Astronomy. Received Jan.20th.I was an early customer who received my H-alpha filter in the winter of 1999. I have been delighted with its performance so far, but would like to inquire if a mounting flange is available to fit my scope ....R.M> Charlottsville Received Jan. 17th. Before I sent the unit back to you for inspection, I decided to take another look just to be sure. I think I may have over-reacted before.......Sorry for the false alarm. And thank you for your quick response and willingness to address my concerns. I value customer service very much, you guys are terrific! So terrific in fact, that I'm considering an upgrade to an AS-90. N.J. USA (Helios owner) Received Jan. 10th. I've put your company up on our solar links page at: http://www.lpl.arizona.edu/~rhill/alpo/solstuff/solinks.html This page is used as an equipment and resource reference by a lot of solar astronomers (amateur and professional) so you should get good exposure. You don't really need it though as you folks are known as the best in the business. Rik Hill Received Dec. 28th. I was very impressed with the Coronado filters, David. Good product! Regards, Dick Buchroeder, Tucson Received: Dec. 26th. I own a Helios I and have enjoyed it immensely, especially today (Christmas day), with the partial solar eclipse we enjoyed here in sunny Dayton, OHIO (at least today!). Paul Martin Received Dec. 21st. ...I had one occasion last week and another 3 days ago to try out the Helios. VERY IMPRESSIVE! Got some great views of prominences both on the limb and superimposed on the disk. I shot some test exposures for next weeks eclipse which should be ready to pick up today. The Helios is a wonderfully portable instrument!. Fred Espenak Check out Solar Chat for more " best reasons" for Solar Observing Received: Dec. 20 From Scott Nord, PA Best reason for Solar Observing: "see an eclipse on a daily basis." Received: Dec 3 Almost everyday I post new images done with Helios I at the ALPOSS web site. Meanwhile I have a web site too, at www.geocities.com/CapeCanaveral/Launchpad/1040/ where daily (everytime the weather allows it!!) I posted solar images and reports. We are trying to build up the Portuguese Network for Solar Observers (includes Brasil).I would like to join Coronado`s List server too. You are free to get any solar images you want from my web site. Best regards J.Porto Gran Canaria I recently purchased a Helios 1 from Kendricks and I love this little scope. I'm truly amazed at what I'm seeing. Steve Lynch, CO Received: Dec.3 - Glad to hear from you - Thanks for the info on the Solar Workshop. Right now, our calendar looks open for that date and Lois and I are planning to attend. Having a great time with the Helios 1. Ray Berg Received: Dec.4 Please feel free to use *this and the further attached image using same equipment. This shows a flare(?) near the limb. After only 40 minutes the associated(?) small prominence had disappeared. I am now taking these whole disk pictures on a regular basis, I can set up the telescope and filter in a couple of minutes so as to make the best of the fleeting windows of opportunity the current UK weather allows! It is fascinating watch the continuing changes in both prominences and filaments. James Weightman, UK *The images are posted in the Image Gallery Received: Dec. 6 Thanks for your prompt delivery of our Helios I solar telescope. Lars Petersen Astronomer Folkeuniversitetscenteret Skærum Mølle Denmark Received: Dec. 12 Have been enjoying the Helios for 6 months and doing lots of solar parties with it. Here are a few quotes for the contest: My other telesocpe is a Helios. See more of the sun with less (.8a), Have Helios, will view, The sun isn't just for mylar anymore, Solar astronomers have more flair, Narrower is Better or Narrower is Better in Ha. I'll think of some more, but consider these the first volley for the contest. Doug and Helen Miller, CA Received: Nov. 7 Congratulations on your patent of the AS design. It is a real revolutionary design. Many thanks also for your continuous effort to bring us new models, like the AS-140, the Helios 180 and the "filter modules". Pedro Santos, Portugal Received: Nov 5 Thanks for all the encouraging comments from you and those forwarded to me re my first efforts with your filter and my CCD camera. I kind of chuckled when the comment was first made that I couldn't reproduce with a CCD the results others were producing with film. (saying the word "can't" or "impossible" near me is like dangling a red flag in front of a bull!). Needless to say, that set me on my way! Jack Newton. See the results of Jack's "first efforts" in the Image Gallery. Received Oct. 21....testimony to the major advantage of Solar over dark sky observing! I am getting some really great images from the filter on the new telescope,(VX 102-ED.with Coronado ASP-60) which is viewing at about f11. Saw the most impressive prominences I have ever seen today. Its great to be doing some observing without loosing sleep! R.Gabbay, CA. Oct. 19th. A comment on Coronado Adaptor Plates. Your machinest did a wonderful job on the plate. It fits like a glove, and is very secure. This transaction has been a breath of fresh air.... R. Gabbay, CA October 17 2000 Dear Mr Lunt, Thank you for taking the time to send me your very prompt reply to my e-mail. I received it in time to make up my mind for the weekend. I bought the Helios.(From Venturescope) The picture you sent swung it for me!*I look forward to a good clear sky. It's a beautifully made instrument,very high quality. H. G-B U.K. *Surface detail photo taken by John Adair through Coronado Helios 1 can be seen in the Image Gallery. John Adair's techniques for the great images he captures are posted in FAQ. The image quality of the Helios I is superb and is also testament to the fine optical quality of the filtering produced by Coronado.I also happen to believe they are an excellent company to deal with and give good honest advice and support. ( I also think they have one of the most open web sites for customers to communicate ie. Solar Chat ) John Adair, UK Received Oct. 3 Monday I took some photographs through the instrument (Helios)and,depending on how they come out, I will be sending you the results.The Helios is working wonderfully. We are still working with the color video camera to get the balance right for projecting the image onto the Planetarium dome.My only regret is that I don't get enough time during the day to do more work with it. I hope next semester will lighten up but,in the meantime I may "sneak" it out on the weekend and play with it to my heart's content. Thank you so much for your efforts in getting it to us,we look forward to many years of solar work.Bryan A. Snow,Planetarium Coordinator, Scobee Planetarium San Antonio College, San Antonio, Texas. Received September 28th. I am the proud owner of an AS1 90 filter system. Used on my 155mm Astro Physics refractor,the visual images are awesome. Steven Menaker, ALASKA Received September 30 Message : I just recently purchased a Helios 1 solar telescope from Kendrick in Canada. IT IS AWESOME! Thank you for giving me the opportunity to see the sun in a new dimension. I am a teacher and have used the Helios 1 with my students. The reaction is WOW! Daniel del Valle Hernández,Puerto Rico Received September 27th. Please find enclose an image taken from the Thetford Star Party. I had great fun with the ASP60 and many people viewed the sun with "wows" !! Regards Adrian Caterall, UK (Adrian's image is posted in the Gallery) Received September 23 In June I received my Helios 1 telescope from Kendrick's out of Canada.The telescope is truly a quality instrument and reveals the sun in great detail....I am hooked on solar viewing. Kenneth Stage, USA Received September 25 Thank you for continuing to be an outstanding company to deal with, you've no idea how good it feels from the customer end. Regards John UK September 6 My ASP-60 arrived today and it is great! Sun, Moon, Jupiter and Saturn, Deep Sky, no time for sleep! Thanks for an eye-opening product. Peter Grieve, USA Received with thanks!Of course its now cloudy, but did manage a peak late in the day yesterday and the sun looked very nice through your filter.Hopefully soon I can get a few decent CCD images Regards Adrian Catterall, UK (Check the image gallery for a link to Dr. Catterall's observatory site.) September 5 The Helios arrived yesterday and was operational within a few minutes!Throughout the day there were only a few brief glimpses of the sun through high cloud but enough to make me appreciate how easy the instrument is to use.I was amazed at the details visible inspite of the poor seeing conditions. It now appears we are in the depths of an Atlantic depression for a couple of days. Once again, many thanks for you prompt attention -you have a very satisfied customer. Regards, Dr. T.Hoy, UK I immediately tried the filter, however, the sun had dipped below the tree-line where I live (about 20 miles Northwest of Chicago, IL). So, the following day,Saturday September 16th, I awoke at the crack of dawn, packed up all my equipment, and headed for the woods.I setup the Pronto that I purchased especially for the ASP-60, attached the filter and pointed it at the sun. What I saw took my breath away!! It was absolutely beautiful. I saw prominences, granulation, filaments, sun spots, plage, and many other features. This filter truly is everything that your web site and the magazine articles say it is. As soon as I become more proficient with using the filter (I have noticed how the various features of the Sun change as you tune the filter) I will start taking pictures and e-mail you my results. You and David Lunt should be congratulated on the fine work that you have done developing and manufacturing these amazing devices. Bill Cosgrave, USA Sept.6 My ASP-60 arrived today and it is great! Sun, Moon, Jupiter and Saturn, Deep Sky, no time for sleep! Thanks for an eye-opening product.Peter Grieve, USA Received August 21 2000 Mr. Lunt: I spent a fair amount of time this weekend and during the preceding week using the AS1-90 system. First, let me say that I am stunned by the absolute simplicity and ease of use inherent in this system.By contrast to other systems that require careful matching of focal ratio, re-heating, and other complex setup and use efforts, I found that even a novice like myself can simply put the Etalon on the front of the objective, the blocking filter at the rear, and obtain great solar views without doing anything more.And setup time is short as well.Performance is equally stunning. This weekend,using 18, 12.5, 7.5 and 5mm Takahashi eyepieces in the Prom -15T, I was able to get full disk images in the 18 with the prominences crisply defined and at least one distinct filament evident even at low power.Using progressively higher power, the surface detail and the prominences could not have been better defined. Magnification up to 160X using the TMB 100mm f/8APO refractor and the AS1-90 worked fine, with one instance (using a 2.5X Tele Vue Powermate)where 265X was possible. To say that I am impressed by this system would be an understatement.It has given me more pleasure in less time than any other piece of equipment in my not-inconsiderable astronomical arsenal.Please accept my compliments to you and your company on developing this fine product. David A. Novoselsky Received August 18, 2000 I purchased my filter from Oceanside Photo and Telescope, in Oceanside, CA. They are wonderful folks. Not to blabber on about the guys at OPT, but they are very responsible for the enjoyment that I get from astronomy, and they called me right away when they got your filters, and are very friendly and knowledgeable. They are big fans of your equipment. Alex Thompson Received August 15,000 I would say, AS1-90 is the ever best H-alpha filter in my past 10-year business experience as a dealer.I mean it would give you the highest resolved image and its the only one available in the amateur astro-market. Morikawa, Tele Vue Japan Received August 9, 2000 Finally, thanks to you and Ken for the prompt action on behalf or the Club Astronomique. There are many suppliers who could take a leaf out of your book on this one. Sue Boyle, Venturescope Received August 6, 2000 I wrote a short note to the solar chat site about my experience with the astrovid attached to my Helios. If you haven`t had the pleasure of viewing the sun on a tv moniter with this set - up you`re really missing a treat.The detail is not 10X as I wrote, but more like 100X that or the eyepiece view!The detail is as good as the Great Bear solar telescope`s picture of the day. I`ve used the set -up with 2x , 3x , and 4x barlows with no image breakdown. The Astrovid 1000 is only $395 ; and the 2000 is only $595; quite affordable. I`ve already clearly seen movement within active areas, and details on the disc only hinted at through the eyepiece. I can`t thank you enough for opening up this most interesting aspect of astronomy to me. Gideon, Hawaii Received August 2, 2000 Message : Had the first proper go of my Helios-1, and wow this is an impressive piece of kit, the views of sun where stunning, anyone interested in solar work should have one, thank you very much:-)A. Bell, U.K Received July 29 2000 You guys are phenomenal in customer care! Joe, Alaska Received July 26 2000 The past Monday received the solar filter. Until today we could not have proven due to the bad atmospheric conditions. The results has been very, very satisfactory, for what we are to you very grateful.The next september I will go to a star party, where we will make known the products of CORONADO and we will carry out observations for the amateurs astronomers. When I take a good images, I will send to you.We will be in contact. Thank you again and greetings, Xavier Roure, IMVO SPAIN Received July 21 Thanks for the helios,I've received it only 3 days back,I've used it ,words can not describe my enjoyment,the picture was more than beautiful,I've recorded it,and very soon I will send you copy of it.Thanks very much. Yours Hasan Ahmad, Dubai Received from a customer in Germany July 18th. BTW: This Helios is just magic, unbelievable details on the surface also on promiences powers up to 150 no problem without image breakdown. I wanted to let you know that we had ~2,000 visitors look through the Ha Telescope (HELIOS 1) that you donated in time for the Jet Propulsion Laboratory open house last month. I will send you a couple pix later. Gilbert Clark, Telescopes in Education Telescopes In Education (TIE) (a non profit education foundation) has served K-12 schools across the United States and around the world for over seven years. We provide free telescope time to educators and students in K-12, and to those colleges and Universities that use it in their educator credential programs. The students remotely link to the telescope and CCD camera, slew the telescope, and image objects in real time. Last year we had almost 11,000 students and educators use the systems. http://tie.jpl.nasa.gov. Received July 14th. 2000 Message : I received a Helios-1 from Kendrick Astronomy a few hours ago. I'm in love! Beautiful scope! Excellent image! I'm really going to enjoy this! Initially the image was rather bland. I rotated the filter and BOOM the detail popped out! I took the scope to my local telescope store to try out eyepieces.Once we got the 8mm piece working, the store emptied out and lined up to take a look.They were all impressed! I expect the same will happen at the star party later this month. Prominances, filaments, plages, spots and even granulation were marvelously clear (and in a hazy Seattle summer sky to boot)! The 8mm piece gives a good sized full disk. Playing with the filter ring helped bring out different features. I also noticed that contrast would improve a bit when the image brightness went down (clouds passing overhead). I tried placing my hand in front of the lens to bring up the contrast, especially of plages. Need to experiment some more with this technique, but it looks promising. It was hard to dark adapt my eyes to see detail. When I got home, I threw a black t-shirt over the diagonal and used it as a hood. Worked well. Will probably get a proper dark hood at a camera store next week. Overall,an excellent scope!It turned out that that my instrument was exactly the unit Sky and Telescope used for their review. If their experience was anything like mine, it will be an excellent review! You should know that I was an astronomy major in college and did an internship at Big Bear Solar Observatory in alifornia. The image through the Helios-1 is comparable to the images I saw through the 12 Singer telescope used for full disk! Very impressive! Thank you for your excellent product! sincerely, -Nikhil Joshi Check out Solar Chat for photography discussion. Received June 1, 200 "I've been testing my filter (ASP-60). That thing is fantastic! wouldn't sell it back to you for$10,000.00". D. Harrelsen, Georgia Received June 5, 2000 "My Helios is used as solartelescope for our public obsevatory Mercurius in Dordrecht( I am a member of the staff), many people has visit us last months and they were suprised with the image of the sun with the Helios,that was for us the reason to buy a second Helios 1 just for public use." Cees Aarnoutse, The Netherlands See some of Cees Aarnoutse' photography in the Image Gallery. Received June 5, 2000 I showed the Helios for the last 3 days at my 10 years anniversary show. All have been extremly impressed. Markus Ludes, Germany Received June 1,2000 Even though you have the pressure of building your business, you've always taken the time to explain something for me - sometimes repeatedly - until the lightbulb finally "comes on" over my head. I've found the subject of H-Alpha filters and Solar observing quite exciting, and something I've longed to get into for 25 years. Connecting with your company now brings my interest to reality,and offers me the chance to learn an exciting new aspect to my hobby. Your direct connection to the customer is a rare and OUTSTANDING aspect of your business. Thank you. Tom Masterson. USA Received May 26, 2000 Thanks for the speedy reply. You folks always floor me with how quickly you reply! Can't say I've ever experienced this level of customer service from any other company before - very rare indeed. MUCH appreciated! T. Masterson USA Posted May 26,2000 "....thank you for your superb solar telescope - Helios 1" J.Porto, Gran Canaria, Canary Islands. (See Joao's latest photos in the Image Gallery.) Received May 25 The AS190 I received today showed us the ever best, dynamic, fabulous, and beautiful images which we have never seen before! Unfortunately my English vocabulary is not sufficient enough to describe what Amatsu and I saw today. Thank you for the excellent product.Morikawa, Japan.(See photo taken by Coronado Japan using the AS1-90 in the image gallery.) Received May 8 I want you to know that I really appreciate the personal attention you and David have given me. I am really enjoying the improved performance - the views are great - surface detail is very good and compares very favorably with the regularly updated Ha images put up on the web by the National Solar Observatory (http://solar.uleth.ca/sunnow/) and the prominences are bright and very detailed - I hope to be able to successfully photograph them but so far have been a bit disappointed with my results. I certainly can recommend your product and especially your customer service. Thanks again, Bob Received May 3 Let me update some informations after spending a second day under sunny sky with the Helios I. Moving from the Helios to my narrowband T-Scanner I found it as an big advantage to be able using the Helios to observe with very low power in an very short compact travelscope on simple Phototripod, seeing the sundisc with lots of space around. On my T-Scanner I am using an Takahahsi LE 50 mm 2" eyepiece and have as minimum an medium power and just enough field to see the disc, but not much space around, so some of the wideview perspective is present in the Helios but not in the T-Scanner. The T-Scanner is used with a long heavy telecentric system, a 2" Stardiagional and an heavy 2" eyepiece, the Helios is simply used with an 1.25" Stardiagonal and lightweight 1.25" eyepiece.The power using the T-scanner recomments an tracking german equatorial mount, the Helios just a simple easy to transport phototripod. So the Helios is a wonderfull traveling Solarscope, the T-Scanner more or less a backyard Observatory Filter. On nthe second day I used the Takahahsi Hi 2.8 mm eyepiece without any visible breakdown, which is very impressive for such an small 70 mm aperature used in the Helios. clear sunny days Markus Ludes Received April 11th. via Ted Wolfe of Florida, the comments of the President of the Everglades Astronomical Society after seeing the Helios at Astronomy Day. "All I can say is "WOW!" You certainly stole the show with that absolutely magnificent instrument. I have never seen such spectacular views of solar flares ever, and to catch them "live" leaves one speechless. Thank you so much for bringing Helios with you to our celebration of Astronomy Day 2000. It will be long remembered." Received April 2 from George Hripcsak /New York. Full comments posted on Solar Chat I just received my ASP-60 yesterday and used it with my Pronto for the first time this morning.Given the recent email of people looking for advice, I thought I would report.I attached the front element to the front, the back element to the back, and stuck a 9mm Nagler(53x) eyepiece in. The first view (no adjustment whatsoever) was pretty much perfect. It is as good a view as any full-disk image I have ever seen on the Web or in a text. It wasn't subtle: prominences, flares, filaments, etc. It was as if someone just pulled a sheet off the sun. It really was impressive. There are currently prominences all the way around and detail throughout the disk. The view was very clean: very little scatter, dark background, and no odd areas or ripples in the image. If you are looking for a beautiful view of the sun and you have a Pronto, then the ASP-60 is clearlythe best choice of all. It is highly portable, very easy to use, and useful over a very wide temperature range. My filter was delievered in 8 weeks, which I thought was good. Even if I didn't have a Pronto, I would probably adapt the ASP-60 to whatever I did have (or buy a Pronto,too). Received March 16,2000 the filter works magnificently --- much better than before I dropped it. Anyway, now I can clearly see the granularity of the sun's disk,with all kinds of breathtaking detail, and the prominences are simply stunning. Unfortunately, the clouds moved back in, so ten minutes is all I have had with the filter so far.Thanks a million for fixing the filter for me. It is now simply marvelous. Best wishes from a happy user. Alan Leighton, Germany March 16, 2000 I received the 60mm Gemini about two weeks ago. After waiting some days for a custom machined adpter I have been experimenting with it for the last week. I must say I am very happy with it. Very clean images, excelent uniformity,black background, no sign of reflections, ghost images or secondary images.Also very stable as I never need to adjust the tuning control. Excelent panoramic view of both disc detail and proeminences. Pedro Santos, Portugal | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ASP-60 and Helios 1 reviews from the February issue of Coelum.90 FEBRUARY 2000 NEW INSTRUMENTS FOR SOLAR OBSERVATION HELIOS-1 solar telescope and ASP-60 filter By Giovanni Dal Lago We present our readers with a world preview of two new solar observation products: the Helios-1 telescope and ASP-60 filter, both produced by the Anglo-American Coronado Instruments Group. Solar observation is not a popular activity among amateur astronomers, probably because it is frequently limited to white light which, embracing the entire visible spectrum, allows the observation of sunspots only and other superficial details of the photosphere. Unless you a true enthusiast, this kind of unexciting astronomy will lead you to abandon solar astronomy, except for occasional viewing or for special phenomena, such as eclipses. However, narrow-band observation, restricted to specific regions of the spectrum, allows us to observe the ever-changing nature of this star; the region aligned on the 6562.8A (Hα) hydrogen line is the most interesting and spectacular: anyone who has had the opportunity to admire the Sun in this band will surely have been struck by the multiplicity and incredible dynamism of visible detail. Coronado Instruments Group is a new Company set up by the American researcher and enthusiast, David Lunt (whom some readers may have had the opportunity to meet at Astron 99 where, among other things, at Coelum’s invitation, he gave a talk on the technology of Hα filters) specialising in the production of filters for solar observation. It was on this occasion that, thanks to the kindness of David Lunt and the Italian importer, Franz, we had a brief opportunity to try out prototypes of the two products now presented. To be truthful, the result was disappointing, but at that time we were looking at two prototypes still in the development phase. This review is based on two randomly selected production models. CIG have now embarked on the mass-production of products including the Helios-1 solar telescope and ASP-60 filter. HELIOS-1 Helios-1 is a refractor with 70 millimetre-aperture and 400 focal length, designed for Hα solar observation, with a band-width of 0.8 Angstrom. 91 This figure is important, this decimal being the figure which tells us the solar details visible through the telescope. In general terms, filters with band-widths of between 1 and 2 Angstrom are intended for the observation of solar prominences but do not permit the observation of details of the chromosphere. By restricting the passband to values in general between 0.8 and 0.5A, it is possible to observe the intricate detailed structure of the solar chromosphere; lower values give better superficial contrast but reduce prominence luminosity. Because of the difficulties and manufacturing tolerances associated with the etalon and coating, the reduction in band-width gives rise to an inevitable exponential price increase. It is also essential to consider two other important factors relating to this type of filter: the angle of convergence of the light cone and heat stability. The former is crucial because it modifies the nominal passband (the actual passband will always be larger than the first value because the greater the focal length and the larger the diaphragm, the closer the two values become). And so, if we observe at f/30 (considering the optimal compromise), we would have a good view of the solar chromosphere, which is enhanced if we increase the f-number, for example, to f/45, but becomes unacceptable if the f/number is reduced to f/20. This is why the American Daystar filters are optimised for observation at high focal lengths. The true innovation of the Helios-1 lies in the possibility of observing the Sun in Hα irrespective of the f-number, actually f/5,7. This feature derives from the special optical design in which the etalon is positioned (towards the middle of the optic tube) between a set of supplementary lenses which allow the angles of convergence crossing the etalon to be adjusted; as if the latter were positioned virtually in front of the objective, but with the benefit that its diameter will be around half that of the refractor’s aperture. A configuration used, incidentally, in some NASA designs. The second important feature of the Helios-1 is the blocking filter, which allows alignment of the passband, subject to displacement due to temperature variations. The instrument is tuned by tilting the filter and rotating a ring-nut positioned in front of the focusser. An ERF (Energy Rejection Filter) is also installed in front of the objective to prevent the entry of ultraviolet and infrared radiation and control the final luminosity of the image. The mechanical precision of this solar telescope is surprisingly high, far above the standard to which we have become accustomed; the helicoid focusser is ultra-fluid and accurate: when the 2" and 1.25" extension tubes, which guarantee focussing using any combination of diagonal and ocular, are removed, we observed a pneumatic reaction attributable to the high degree of manufacturing precision. ASP-60 The ASP-60 is a filter designed specifically for the Tele-Vue Pronto telescope and is made up of two parts, the filter (etalon) to be placed in front of the objective and the blocking/prominence filter for tuning, as in the Helios-1. In the model tested, the blocking filter, is integrated in a 1.25" diagonal, but the direct 2" version, definitely more appropriate to photographic use, is also available. A small screw positioned on the diagonal, by tilting of the filter, allows entry to the band. The ASP-60 has a useful diameter of 60 millimetres and band-width of 0.7A. 92 It is curious also to note the filter’s central obstruction. The main benefit is that the filter, being installed in front of the objective (screwed to the Pronto’s ED doublet thread), does not suffer from the problems associated with the angle of convergence of the light cone. In practice, the ASP-60 is designed so that the band-width covers the subtended solar diameter angle, approximately half a degree (to be more precise, the specifications refer to +/- 0.26 degrees). Also, although the filter is mechanically designed for the small Tele-Vue, it can be installed on any instrument and in any optical configuration. THE TEST We conducted an initial high-speed test on the Helios-1 and ASP-60 filter, the latter being installed on a Pronto, mounting the instruments on a simple photographic tripod in order to ascertain its ease of use and set-up speed. The compactness and overall design philosophy of these products give them a practical versatility far in excess of that of the conventional Daystars. In both the Helios-1 and ASP-60, from the outset we found the prominences around the solar disk to be highly visible, due also to moderate activity in the Hα region. The tuning procedure vis-à-vis the blocking filter, consisting in the rotation of the Helios-1 ring-nut and the ASP-60 diagonal screw, facilitated fast accurate tuning of the passband. Numerous details of the solar chromosphere then became clearly observable: flares and magnetic regions around sunspots, filaments (prominences projected on to the solar disk), some of striking dimensions, and also granulation. During this initial test we noted that in Helios-1, once the instrument had been tuned, the solar disk has to remain in the same approximate position within the ocular, with a small displacement margin, to avoid total loss of vision of the chromosphere. Also, if positioned slightly off-axis (south of the ocular field), the image visibly improved. If the instrument is not fitted with a motorised equatorial mounting, it will require a minimum of attention for the occasional repositioning of the solar image in the ocular field. In this respect, the ASP-60 performed better; the chromosphere was in fact still observable even with the solar disk at the edges of the ocular field. The diverse behaviour of the two instruments derives, as we have already said, from the different optical design: the positioning of the etalon in front of the objective lens guarantees an actual band-width virtually equivalent to the nominal value. A second more detailed test was carried out by installing the two refractors in parallel on a Takahashi CN-12 in Cassegrain configuration, diaphragm f/29 with a rejection pre-filter (ERF) of 90 millimetres aperture and a Daystar ATM 0.6 Angstrom Hα filter. Since we were well aware of the quality of this reference filter, the possibility of a direct comparison of the various images offered by the three instruments allowed us to carry out a more objective evaluation, as summarised in the table below. Having tuned all the instruments and attempted, where possible, to standardise the various magnifications, using different focal lengths for the oculars (with magnifications from 31X to 44X), we carried out an initial observation on the solar prominences which, in Helios-1, were found to be decidedly clearer and more luminous than in the ASP-60 and the ATM Daystar, due, in all probability, to the wider passband (0.8 A) of the solar refractor. Observation at such small magnifications (a 60 mm Celestron Ultima had been mounted on the Takahashi) was truly spectacular: the opportunity to observe the entire solar disk surrounded by numerous prominences was a sight not to be readily forgotten. Maintaining the same magnifications, we then began observation of the star’s surface; on this occasion the ASP-60 came out best, due in particular to the flares, more contrasting than those visible with other instruments. 93 But Daystar offered almost the same surface details, which in Helios-1 were less well-contrasted. At only 31 magnifications, the image in the latter was perhaps a little too luminous. Increasing the magnifications (70X-90X), vision with the Takahashi was better; the Daystar had a larger reflection pre-filter aperture (90 mm) which, in addition to guaranteeing better resolution, maintained adequate luminosity. At these magnifications, in the ASP-60 luminosity fell drastically; however we must take into account that we conducted the test in the winter period when the Sun is certainly not at the Zenith. This difference, also evident in comparison with the more luminous Helios-1, is due not only to the narrower band-width of the ASP-60 and the higher f-number of the Pronto (which in this configuration operates at f/8), but also to a secondary filter, frontal to the blocking filter, slightly darker, necessary to prevent internal reflections between the latter and the frontal section. We found in fact that the ASP-60 provided images wholly free of axial reflections, whereas, with the Helios-1, these were visible in certain positions. CONCLUSIONS We award full marks to these two new products from Coronado Instruments Group. Direct comparison with a filter of unexceptional quality, such as the ATM Daystar, allowed us to establish that both the Helios-1 and the ASP-60 provide high-quality images in terms of the declared specifications. In addition, the possibility of observation and photography with such low f-numbers makes these instruments ideal for CCD images of the entire solar disk, a process until recently impossible for amateurs. If we had to choose between the Helios-1 and the ASP-60, it would frankly take us some time to decide between the integrity and versatility of the former and the slightly better vision of the latter. Finally, the Helios-1 should be regarded as a potential acquisition for associations, clubs and schools, on the grounds of the incredible educational value offered by this instrument.
HELIOS-1 ASP-60 TESTED BY COELUM TESTED BY COELUM
CAPTIONS PAGE 90 In the Helios-1, the blocking filter is tuned by rotation of the ring-nut fitted in the optic tube. PAGE 91 Top: the ASP-60 filter, mounted and screwed to the ED doublet of the Tele-Vue Pronto: note the unusual central obstruction of the filter. Right: with the ASP-60 the band is aligned in the Hα filter line by rotating the small screw positioned on the 1.25" diagonal. Below: The Helios-1 solar refractor telescope: with the two extension tubes (2" and 1.25") it is possible to obtain initial approximate focussing; precision focussing is achieved with the helicoidal focusser. PAGE 92 For a comparative test, appropriate instrumentation is required. In this suggestive picture, we see the three telescopes used in the test, trained on the Sun. The three instruments installed on the MB50 mounting during the comparative test. At the top, the reference instrument, a Takahashi CN-12 with ERF pre-filter and ATM Daystar Hα. In the centre, the Televue Pronto with ASP-60 filter. At the bottom the Helios-1 solar telescope.
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SolarMax, AS1-90, and ASP-60 H-Alpha Solar Filter Reviews. Coronado versus Daystar editorial.These are unsolicited reviews posted purely for customer information. Read recent reviews of Coronado's SolarMax filter by Doug Finch and Peter Ward. Read reviews of Coronado's ASP-60 and AS1-90 by David A. Novoselsky hosted by Cloudy Nights.Read the H-Alpha Showdown! CORONADO versus DAYSTAR by Doug Finch | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
About UsDavid Lunt and Geraldine Hogan co founded Coronado Technology Group, LLC in February 1997 from their home in Pearce, AZ. . David Lunt has been developing ultra-narrowband filters and associated technologies for well over forty years, resulting in many technically sophisticated models for numerous applications in the fields of space, astronomy, lasers and Lidar and high resolution spectroscopy with a principal customer base of scientific and Government institutions from around the world. Coronado was founded with the specific purpose of providing innovative optics specific to the needs of the amateur and professional Solar observer. Due to breakthrough innovations, on which we hold patents, we are now able to bring this technology to the amateur scientist and hobbyist. As amateur astronomers ourselves, we are very pleased to be able to do this. Our most recent and significant break through has been in the development of the P.S.T., an integrated H alpha telescope at the amazing price of $499.00, this follows our SolarMax , a 40mm Ha narrowband filter.It has always been a goal of Coronado to bring to the market instruments of high quality at affordable prices. We believe that by providing instruments in a price range that makes the filters accessible to more people, we are opening the hobby to a wider market and ensuring the future of Solar observing for the amateur market. We have a particular interest in education and opening the hobby to young children. With this in mind, all of our instruments are completely safe and easy to use, as such they make an excellent teaching tool. We received the following comment very recently from a teacher: "This time last year we had no astronomy program at the school. Now we have 12 telescopes, 2 Coronado H alpha Solar filters and 700 budding observers! Our Coronado filters are outside and in use whenever the Sun shines. I invite teachers contemplating an astronomy unit, particularly Solar, to get in touch with me. I'd be happy to discuss our program". Daniel Poccia, Iona Prep. School, New Rochelle, USA tel: 914-632-0714 e-mail drp79@ionaprep.org At Coronado you have colleagues who are as passionate as you are about observing and about the right equipment. We are happy to talk "shop" with every customer from beginner to accomplished observer. Please do not hesitate to get in touch with us to further discuss your interests, and how one of our filters can enhance your enjoyment of the world of astronomy by opening up the ever-changing, turbulent events in the daily life of our sun. In 2005 Coronado introduced the first of its production line of CaK telescopes, the CaK 70mm. This was followed by the launch, in November 2005, of the P.S.T. CaK model. The CaK 70 was awarded a Sky and Telescope Magazine Hot Product designator for 2006. For the past 5 years, a Coronado product has received this coveted award. In 2004, P.S.T was awarded a "Best of What's New" designator by Popular Science Magazine in the Space and Aviation Category. Our goal has been to put together a vertically integrated manufacturing process that leaves us in control of every aspect of production from coating to assembly and, one that will alleviate the long waits commonly recognized as the norm in the manufacture of high quality optical instruments. Since 2000 we have been located in Tucson , Arizona where we have a full optical shop, assembly and test area. We welcome visitors, by appointment, between 11:00 a.m. and 2:00 p.m. Monday through Friday. In October 2004, Coronado's assets were acquired by Meade Instruments Inc. a California Company, Coronado Technology Group is no longer involved in optical manufacturing, the new company is Coronado Instruments Inc. and it is a California company. David Lunt, the co founder of Coronado, passed away, January 2005. His wife and partner Gerry Hogan continues to organize the only annual conference on Solar observing for the amateur astronomer. Hands on the Sun (HOTS) is held in October in Tucson. Coronado's goals remain unchanged: · Produce the finest filters possible within an affordable price range. · Deliver on a timely basis. · Provide exemplary customer service. · Be available to our customers. · Select to represent us those dealers whose reputation is superb. Should you have any questions about our products please contact us directly. Coronado: 1674 South Research Loop Suite 436, Tucson Arizona, 85710 Local Telephone: (949) 451-1450 ext. 352, Fax: (949) 451-1460 Toll Free Telephone: 1-866-SUNWATCH (786-9282) General inquiries: info@coronadofilters.com | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CURRENT NOTICESJuly 22, 2003 Blocking Filter Safety:A recent spate of Astromart postings indicate an interest in double stacking by acquiring front elements. Please be aware that Coronado blocking has always been and is 100 percent safe, however, design changes in elements of the filters means that NOT ALL BLOCKING FILTERS can be indiscriminately paired with any front cell unit. Please check with Coronado before attempting pairing with non factory supplied combinations. We'll be happy to help. We'd like to caution people that you cannot swap Coronado blocking filters and narrowband front elements ad hoc without the risk of compromising safety. On no account, pair a blocking filter from an Isle of Man production run (AS1 series filter) with a US produced SolarMax series filter. The blocking elements have been reconfigured in the newer models and the older blocking filters are NOT compatible from a blocking perspective. We can retrofit additional blocking to older blocking filters. We strongly advise anyone considering pairing a front narrowband element with any blocking filter (other than the one it was originally supplied from the factory) to contact customer service at nicholas@coronadofilters.com to determine if additional blocking is required. Coronado will not be held responsible for problems caused by improper matching of filter elements. Gerry Hogan President Coronado Technology Group June 7 2003 Coronado was the recipient of the 2003 Clyde Tombaugh Award for excellence in technical innovation at RTMC 2003. Please accept my heartfelt congratulations regarding your award and recognition at RTMC for your incredible contributions to solar observing. Not only have you "created the market", but you've created the technology and products that have enabled the amateur community to observe the Sun like never before. I see Coronado equipment and enthusiasts at every star party I attend now, and it's great! It really is a whole new world to explore. Craig Anderson, CO Your solar instruments have changed my whole focus and study in astronomy. It has given me "passion" for the sun! Your company deserves every award it gets. I am going to be the best solar astronomer I can be and I am so happy that your solar instrument has allowed me to study the sun...and all it's glory! I was accepted into the CUREA program at Mt. Wilson for 2 weeks in August. I will be able to do some intensive research at the solar facilities on Mt. Wilson. Carmelita Miranda, CA April 15th. Customer Service is imporant to us! "I've written you several times in the last week requesting information in my pursuit of a Solar set up. Your responses have been fast, accurate and trustworthy. If my new Maxscope40 is of the same quality as your support, I'm in for more of a treat than I was hoping for." Mike S. Posted February 12 2003 Coronado Ha filters and dedicated telescopes now have a 5 year warranty. As in the 1 year warranty, etalon breakage or decontacting is not covered nor is any damage to the blocking filter. These situations are user induced (albeit unintentionally!)Watch this space for information on our self insurance policy which will cover etalons and blocking filters. The instruments manufactured by Coronado are unique in technology and fabrication methods and have tolerances and specifications that are so demanding that very few sub contractors exist to support our needs. Consequently we rely on a few, select sub contractors and our own in-house capabilities. It is not possible for us to predict to the day a delivery schedule. Given the precision involved there are many variables that can and do affect production time tables. We assure you that we have a full crew working up to 10 hours a day and that we put major emphasis on production numbers. However, we have not yet, nor do we intend to, shipped a product that failed our very stringent tolerance tests. We emphasis quality over quantity and trust that in the interest of receiving one of the finest Solar viewing instruments available to both the professional and amateur observer, you will be patient and understanding of any delays in receiving your order. Please contact us at any time for an update. We know the rumour mill can often provoke unnecessary angst and we urge you to come to the source should you have any questions. Gerry Hogan President, Coronado gerry@coronadofilters.com August 17th.2001 MEADE ETX 60/70 SERIES TELESCOPES: Due to the VERY LIMITED focus range of these two telescopes we have determined the need to accomodate Coronado customers who want to use these instruments in conjunction with SolarMax. To that end we have designed and are in the process of producing a blocking filter unit sepecific to the Meade ETX 60/70 models. This will be available by September 15th. Customers who have already received a SolarMax for use with either of these telescopes will be provided with the new blocking filter unit as soon as it becomes available. We apologise for any inconvenience. July 26th.2001 My Solarmax arrived along with the adapter plate for my Tak FS 60c (thanks Astronomics!) and I managed to make an observation during my lunch break. With 19mm Panoptic the disc was small but showed surprising detail. The huge prominence that everyone has been talking about along with several nice small ones, three dark filaments and nice mottling on the disc. Very bright and crisp image. I went to the 8mm Radian and the disc was much larger. Proms still showed well, but the disc was much dimmer. I was pressed for time and was not able to use my headcloth or experiment with other eyepiece combinations. I can't wait to put it through the paces this weekend! I will post a review on Cloudy Nights in the next few days. I think congratulations are in order to the Coronado team for a product that could revolutionize solar observing. A true sub angstrom filter that is safe and affordable. Good job Gerry and David! Everyone who have been patiently waiting will be pleased! > Best, > Doug Finch > March 8 2001 HOW SOLARMAX ™ WAS SELECTED When we opened the naming of the new filter to the general community we had several goals in mind. One, obviously, was to derive benefit from the vast number of creative minds that would enjoy the challenge. The management team had spent hours mulling over the question of a name and judging by the names given our original filters ; AS1-90, ASP-60...creativity was not our forte! It was an amateur observer whom we met at OPT in California who suggested issuing the challenge. The names poured in and many were extremely creative and at a first glance were pounced on as "that's it!"only to be discarded in favour of the next one we termed "brilliant". About a week ago the management team culled 27 names from the many submitted that we felt met our primary objectives : i.e. product appropriate, would look good on a label, was easy to pronounce and remember and, had a good chance at gaining trade mark status. We sent this list, along with a description of the filter, to a group of 40 or so friends and associates and asked them to select their 8 favourite names and rank them 1 -8. NOBODY who had submitted a name was involved in this process and no names were attached to the suggestion. The five names that appeared the most frequently were then subjected to a similar round of informal voting but this time we solicted input from people we knew to have professional experience in sales, marketing,advertising and graphic design and asked them to select top two choices. SolarMax & SolMate came out clear winners. The final process was to send those two names to a sampling of our dealers in different parts of the world (we wanted to make sure there was nothing culturally offensive about either name) and ask them to make their choice. SOLARMAX took all but one vote! Perhaps not very scientific but certainly fair and thorough. DECEMBER 13, 2000 -------------------------------------------------------------------------------- CORONADO OBSERVATORY SERIES During the past 35 years , we have designed and developed many variations of the narrowband filter for use in the fields of Astronomy, Space Optics, Industrial Spectral Analysis and Interferometry. The Helios 1, ASP-60 and AS1-90 models represent some of the simpler, easy to use versions of these, making them ideal for the average amateur with an interest in observing the Sun and even as monitors in professional instrumentation. The Coronado "Observatory" series of filters is being offered to the more serious amateur, the professional and the dedicated Solar Observatory. These filters offer combinations of large aperture, tunability and even computer controlled adaptability, and are intended for installation on large, dedicated, observatory class telescopes. In addition, some of them can be supplied with integrated optical imaging systems. A brief description of the various models follows. These instruments are supplied directly from the factory and are built to custom order. Our technical personnel should be contacted to discuss integration with your equipment and to ascertain final pricing and delivery schedule information. AS1-140 This is a large aperture version of our AS1 series filter. As such, it is a thermally stable, fixed wavelength filter. The aperture of 140mm is optimised to resolve the fine structure of Solar surface detail while keeping to a minimum the effects of poor daytime seeing conditions. As with all of our filters, of course, the AS1-140 can also be configured into the optical train of an existing large telescope. Ancillary lenses and mounts to do this can be supplied to optimise the overall performance of the filter. Full Solar disc, non-degraded spectral performance, can be provided for telescope apertures up to twice the aperture of the filter. High resolution, small area field performance can be gained from even large aperture instruments. Other custom configurations of the AS1-140 are available including tunable versions and adaptive optic systems with computer controlled feedback. In addition these can be supplied integrated with telescopic imaging systems. Coronado technical personnel should be consulted for further details. The AS1-140 is normally supplied with the standard BF-30 blocking filter unit. Other blocking filters for special applications can be designed and manufactured in collaboration with the customer. The next availability is November 2003. Two units available. Specifications: Clear Aperture: 140mm Bandwidth: <0.7A Thermal Stability: <1A/300°C (in air) <1A/2,000°C (in vacuum) Standard Wavelength: 6562.8A (Ha) Optional Wavelength: 3934A (Ca-K); 10,830A (He-I) Price: on request ASM-40 Based on the AS1 series design, this is a thermally stable, fixed wavelength filter. The main difference from the standard AS1 series is that the ASM-40 has an unobstructed 40mm aperture, i.e. it does not have the central obstruction that is standard in the other AS1 series units. The ASM-40 can, therefore, be configured in a slow focal ratio, converging beam if desired or in series with a standard telecentric unit . The other AS1 series filters require ancillary lenses to put the filter in an afocal position and, thereby, eliminate the effect of the central obstruction. However, we recommend using the ASM-40 in a focal ratio of at least F/45 so that the spectral characteristics are not unduly compromised. The standard blocking filter is the BF-30 and an energy rejection filter (ERF) can be provided to suit the particular telescope. Availability: January 2001 and thereafter on a monthly basis determined by pre-orders. Specifications: Clear Aperture: 40mm Bandwidth: <0.6A Thermal Stability: <1A/150°C Standard Wavelength: 6562.8A (Ha) Optional Wavelengths: 3934 (Ca-K) Price: FROM: $3,360.00 Ha System. Other lines quoted on request. SMn-35 This is a "solid spacer" style of narrowband filter that requires temperature control to maintain passband position. The SMn -35 is essentially the same as the first narrowband filter developed by us in 1965. Unlike the version based on Dobrowolski's suggestion of using mica as the spacer layers, however, these are optically fabricated from Fused Silica. This allows us to apply ultra hard coatings to give unlimited lifetime, something that is not possible, using standard techniques, with the mica. The SMn-35 is supplied integrally mounted in a thermally controlled cell. Adjustments to the set temperature will result in the passband being tuned around the spectral line by +/- 1A or so. This allows the passband wavelength to be optimised for individual Doppler shifted phenomena. Attachment to the telescope is either by M42 standard 'T' thread or 2" adaptor. The BF-30 blocking filter attaches directly to the back end of the SMn-35. The energy rejection filter (ERF) required by this unit, is available separately to suit the individual telescope. Availability: early November 2000. There are two units still available from the first production run and thereafter in limited quantities based on pre-orders. Specifications: Clear Aperture: 35mm Bandwidth: <0.6A Thermal Stability: ~1A/20°C Tunability: ~+/- 1A Standard Wavelength: 6562.8A (Ha) Optional Wavelength: 3934A (Ca-K) Input Voltage: 12VDC Price: FROM: £3,600.00 ($5,760.00 North America) AST-35 Housed in the same cell as the SMn-35 , the AST-35 is a fully tunable variation. An air-spaced filter, similar in construction to the AS1 series, it has the characteristic that a change in temperature of ~ 12°C will tune the etalon through one complete order of interference. The result of this is that, not only can the filter be adjusted rapidly around the spectral line of interest, but it can also be re-tuned to other spectral lines within the reflective range of the coatings. Thus by merely interchanging the blocking filter (and, sometimes, the ERF) other lines in the Solar spectrum can be observed using the one narrowband element. The AST-35 is supplied with the BF-30 blocking filter. BF-30 units for other wavelengths are available as an option. Consult the factory for special configuration information and for custom ERF's to suit the telescope. Availability: limited number early November and thereafter in limited quantities determined by pre-order. Specifications Clear Aperture: 35mm Bandwidth: <0.6A ( @6562.8A) Thermal Tuning: 1A/°C Usable Range: 3900 - 6800A (Bandwidth Varies) Input Voltage: 12VDC Price: On request The Observatory Series filters are available directly from CORONADO and a deposit is required to secure a firm delivery date. Since these are non standard items and are made to order, a minimum cancellation fee of 10% will apply to orders cancelled once manufacturing is underway. For additional information please contact Coronado at info@coronadofilters.com A WORD TO THOSE FRUSTRATED IN ATTEMPTS AT SOLAR PHOTOGRAPHY! Following a reveiw of the Helios 1 and ASP-60 performance in Coelum, the premier Italian astronomy magazine, editor and reviewer, Giovanni dal Lago was asked if if solar prominences are easily and clearly seen through the Helios, because in the picture gallery, in the opinion of this particular reader, there were not seen any good picture of prominences. dal Lago, who is considered to be one of the finest solar photographers had this to say..... "Visually, prominences are very clearly seen, MUCH better than through a Daystar 0.6 ATM filter.In regard of pictures: nobody has still taken very good pictures because it is not easy at all to take that kind of pictures.Problems related to solar photography are quite similar to those involved in high resolution planetary imaging." KEEP TRYING! We're happy to post your images and just wish we had the time to get out and make some attempts ourselves! Coronado Instruments reserves the right to change and improve products without notice. Changes will be published on this site. Every once in a while someone asks "What level of customer support do you offer?" Perhaps this e-mail received February 8, answers that question. Hi Gerry, Received the adapter plate today and it fits great. Thanks so much for your attention. I must say I have felt very fortunate to have been able to do business with you folks. The ASP-60 is a delight - I'm frustrated at not being able to use it more but have been working excessive hours photographing the New Hampshire Primary for the past month. The few times I've been able to observe with the filter have been delightful, it so neat to be able to see the increasingly active prominences. You and your staff are to be commended for the fine job you've done and your excellent business integrity. Thanks again. Bob LaPree We offer 100% customer support. As far as we are concerned, compromise on quality and customer support is simply not an option. We have two maxims at work here. 1. Develop the best possible products. 2. Stand behind those products. Whether you buy through a dealer or directly from Coronado, the support is the same. Every filter/telescope is thoroughly field tested by direct Solar observation at least two people before leaving the premises. We ask that distributors re-check for any possible shipping damage before they pass on the filter and we ask that the final recipient also check as soon as possible for any possible defect/ damage. In the few possible "defect" situations we have encountered, the problems turned out to be user learning curve. We'll talk , e-mail or fax the customer through a learning curve. We gladly answer any type of question we're asked and, whenever possible, do so within 24 hours of being asked the question. And it goes without saying, if it's a problem that persists, the customer has only to ship the item back here and, we'll give it our immediate and thorough attention. Since July '99 we have shipped in excess of 3,000 filters/telescopes. To the best of our knowledge, not one of those owners of a Coronado instrument has experienced a problem that has not been promptly and courteously resolved.. On the contrary, the good reviews keep coming in. One of the latest being from Giovanni dal Lago, well known & experienced observer, fine Solar photographer and, editor of Coelum Astromia , the premier astronomy magazine in Italy. Mr. Dal Lago received both an ASP-60 and ,an Helios 1 , through a dealer and he writes: "In this moment I have finished my test on two new products: Helios-I and ASP-60, Ha telescope and filter from Coronado Instruments Group. Helios-I and ASP-60 are very impressive products…." Dear Mr. Vespa, The Helios shows the prominences very crisp and clearly, it`s a very interesting instrument. I`ll write about it in our club magazine (300 members) issue May, and if you don`t mind, I will put your (Franz Foto Ottica)address in it. yours, sincerely, Emil Nietlispach, Switzerland. And an old customer in Washington state: "….again as always, your willingness to keep your customers happy is greatly appreciated" And today from Gideon Knapp in Hawaii; "Thank you so much, you are an incredible company to deal with." If you have a question about our products, our service, our commitment to quality, please contact customer service at info@coronadofilters.com fax: e-mail: adairjs@ibm.net Jan. 31,00 Message : Dear David, Just a short note to let you know I am delighted with the Helios 1 I have taken delivery of recently. The telescope performs just as you claim it would, prominences,filaments, flares etc are extremely bright and clear. Together with the Celestron G3 equatorial mount the combination of optical excellence and mount stability is a pleasure to use. I will be acquiring a CCD camera shortly and forward any good shots for your use, although I think it will be hard to capture the beauty as seen at the eyepiece.John Adair, UK Gerry, Helios is a wonderful instrument. James Blackstock, Out of This World, Medocino, Ca PLEASE NOTE THAT PRICES ARE SUBJECT TO CHANGE WITHOUT NOTICE. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
HELIOS 1 REVIEWThis unsolicted review was posted in Scie-Astro-Amateur in June 2000. A Coronado Helios I H-alpha solar telescope was just delivered to St. Petersburg Junior College. This scope was purchased (with grant money) through Kendrick Astro Instruments. Delivery was about 4-5 weeks after placing the order. As I mentioned in a previous post, we had originally ordered a Daystar ATM filter through Astronomics, but after a very long wait (over 6 months) Astronomics informed us that they could not honor the order because of difficulty in contacting Daystar. Other Daystar dealers we contacted (including Astrophysics and Company 7) were also reluctant to place an order for the same reason. I know that several individuals have indicated that Daystar is still up and running, and accepting orders for their solar filters. Perhaps so. All I can say is that we tried desperately to order a Daystar filter, to no avail. We finally decided to place an order for the Coronado instrument as a "last resort", because we had to spend the grant money. I say as a "last resort", because I read the very negative posts about Coronado on this newsgroup, most of which concerned lengthy delays and missed (promised) delivery dates. Also, I have used the Daystar filters and I know them to be of excellent quality. It made me nervous to commit college money on the Coronado filter without seeing any positive reviews. Anyway, we ordered the Coronado filter and I am happy to report that we received it in a timely manner, and, after a brief tryout, it appears to be an excellent instrument. It is about the same size as a Short-Tube 80, (although 70mm aperture), and a bit heavier. Workmanship is excellent, black anodized aluminum + gloss white tube, would look right at home piggybacked on an astrophysics refractor. Two-inch helical focuser, very smooth - just the right amount of friction. It has standard threaded hole for mounting on a photo-tripod. Very portable and ready to go right out of the box - just insert a star diagonal & eyepiece. Attractive aluminum carrying case. This is a short focus instrument (f/5.7) and has a correspondingly small image scale. It is rated at 0.8 angstroms bandwidth, but I found the contrast and level of detail visible comparable to my 0.6A T-scanner. When used visually, I found that a 17mm eyepiece gives an acceptably large, full disk image. The image had excellent contrast, with a pitch black background. Dark filaments and bright active regions stood out clearly with good contrast. Prominences were bright and crisp against a black background. An important difference between this filter and a Daystar filter is the small f-ratio. The Daystar filters require a very narrow f/30 beam, usually accomplished by stopping down the main telescope. I have found this to be the main drawback of the Daystar design (for visual observing) because at f/30 the most obvious features seen are not on the sun, but in my eyeball! If you have a lot of "floaters" in your eyeball, viewing the sun in a Daystar filter can be very frustrating. I would rate the Coronado filter as much more comfortable and relaxing to use visually (an especially important advantage for novices and the general public). Not a floater in sight! One minor drawback I noticed (and which is made clear in Coronado's literature on the Helios) is that the solar image must be offset from the center of the field of view to ensure that it is in the H-alpha passband. This has something to do with the design of the filter system (etalons, blocking filters and so forth - I'm not an expert on this). In fact, if the sun is centered in the field, it resembles a white-light image (though red in color, of course). I had to position the image about halfway between center and edge to get a full-disk H-alpha view. I think a perfectly centered image is more aesthetically pleasing. In fact, this seemed to be the primary method of "tuning" the filter -- by moving the image around the field of view until H-alpha features became visible. Although this scope can be easily mounted on a camera tripod, the need to constantly reposition the image so it lies within the H-alpha field of view is something of a nuissance. I would recommend piggybacking it on a motor-driven telescope. The scope has a "blocking filter adjustment ring" which tilts the blocking filter to accomodate shifts in the passband caused by differences in temperature. According to the instructions, this ring should be turned to maximize image contrast; however, I found that this produced little if any effect. The instructions state that the H-alpha field of view may be "slightly" displaced from center depending on the tilt of this filter, but I found the displacement more than "slight". However, it was a very hot day (92 degrees) and I'm guessing that at more moderate temperatures the image may be more nearly centered. I was somewhat concerned that the off-centered H-alpha field of view might prevent video imaging in H-alpha. This was not the case. I used an Adirondack B&W CCD video camera. This required quite a bit of back focus, and so I coupled the camera directly to the star diagonal (an extension tube would be preferable). The solar disk fit perfectly on the video monitor. The view was quite stunning -- crisp detail over the entire disk. This required playing around with the shutter speeds and contrast controls. (I am still not sure why the visual offset does not translate to the video image). I also tried the camera with a 2x shorty barlow. This gave a very pleasing half-chord on the video screen, with exquisite H-alpha detail. I found the best way to bring out prominences was to simply increase the gain. This overexposed the disk but showed the prominences quite well. My Daystar T-scanner also gives beautiful video images, but the field of view is much smaller. In fact, these two filters compliment each other quite nicely. As far as I can tell, you cannot get a full disk still or video CCD image of the sun in H-alpha with a Daystar filter (unless you use a Short-tube 80 stopped down to 1/2 inch!). However, the Daystar still excells at showing detail in prominences and active regions. In summary, based on just a cursory examination, the Helios I seems to be a superb solar telescope giving great views both visually and on video. It's also a good-looking instrument. I hope that Coronado has fixed their production problems, because they can really fill a niche in the market. Craig Joseph Profesor of Astronomy St. Petersburg Junior College Note from Coronado: Since October 2000 Coronado has been shipping Helios 1 telescopes from stock. Maxium wait time on the majority of our instruments is less than 4 weeks. Educational groups please contact us directly for information on packages. info@coronadofilters.com | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
About the Central ObstructionThe Central Obstruction A noticeable characteristic of the SolarMax series of filters is the central obstruction. This is an extremely important part of the design and is, in fact, the principle of the patents issued. Ultra-narrowband filters are based on the Fabry-Perot etalon. This can be of either a solid spaced or air-spaced design. Because the solid spaced etalon is constructed of an optical material, such as glass or fused silica, the temperature coefficient of the material combined with the temperature coefficient of its refractive index, mean that the etalon is thermally sensitive and has to be kept at a constant temperature in order to maintain the tuned wavelength. Air-spaced etalons have been constructed for many years as an alternative based on their thermal stability. However, in this respect, one has to carefully define the thermal stability. For instance, if such an etalon is tuned at a temperature of 20degC and the temperature is changed to 30degC, it will also be tuned, and have the same characteristics, at this new temperature WHEN THE WHOLE ETALON HAS COME TO THERMAL EQUILIBRIUM at the new temperature. However, it will NOT be tuned during the time that the temperature is changing and its bandwidth will be considerably BROADENED, due to thermal gradients within the components, causing distortion of the air-gap. Such an etalon, when used as a Solar filter, will have unacceptable, variable characteristics and, therefore, performance. As with the solid spaced filter, it would have to be temperature controlled. It was this dilemma that prevented the use of air-spaced etalons as Solar filters until the breakthrough brought about by the patented Coronado design. The reason for this, of course, is that, in use as a Solar filter, facing the Sun,- the filter is never in thermal equilibrium due to continuous incident radiation. In the Coronado design, an extra ‘spacer’ in the etalon, controls the shape of the etalon components during temperature changes and maintains all the etalon’s characteristics. Thus the filter is kept tuned to the correct wavelength, and maintains its proper bandwidth, at all temperatures and UNDER CHANGING CONDITIONS. This CAN NOT be the case for an etalon that does not have this controlling central spacer. Because of this central spacer, a mask has to be put over the center of the filter to prevent direct sunlight from getting to the image plane. This is the same situation as the central obstruction in a Cassegrain type telescope (or a SCT or Newtonian or Maksutov/Cassegrain). However, whereas a typical cassegrain has a central obstruction of approximately 35%,- giving an area obstruction of ~12%,- that in the SolarMax filters is only 2.5% to 5.5% depending on the model. This is well within the obstruction generally considered to be completely unnoticeable to image quality. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Post your image in Solar ChatProcedure courtesy of Paul Hyndman. Several people have mentioned the desire to share their images here in the "Solar Chat" section, but were unsure of how to do it. Ergo, the following brief how-to: 1) The image is not stored here, so must already be present on some other server elsewhere. If you do not have your own web-site or access to one now, you can post a JPEG version of the image to one of the free services such as: http://geocities.yahoo.com/ http://www.pbase.com/ 2) Fill in the "Post a New Message" info here the way you normally would, with a message describing the image or other particulars you want to pass along. 3) Go to the lower box, labeled "Optional Image Url" and insert the URL of the image you wish to post. If you are unsure of the exact URL, just go to the image (wherever it is posted), position the mouse over the image and "right click" on it. a box will pop up that includes "Properties" on the bottom of the list. Left click on "Properties" and a box showing the image URL will come up. That's the address you want to put in the "Optional Image URL" box, and it should end with ".jpg" (ie: http://www.astro-nut.com/sun-surface09sep02.jpg) 4) That's all there is to it... now select the "Post Image" button and your message and picture will come up! If you'd like to include a link to a page on the web, you can use the "Optional Link URL" box to do so. Just insert the link there, which can be an image (.jpg) or page (.html). You can then use the "link Title" box to caption the link with whatever you'd like. For this example, I am posting the picture "sun-surface09sep02.jpg" by putting its URL in the Image URL box: http://www.astro-nut.com/sun-surface09sep02.jpg and optionally making a link to the full page that it is on (so as to include the other info I want to pass along with the image) by posting the link URL in the appropriate box: http://www.astro-nut.com/sun-ha-09-sep02.html (note that the link is also active on the screen if posted in the body of the message as was done here). Then making a name for the link and posting it in the "Link Title" box. Let's call it: "Here's how to post an image and link!" Hope this helps, and hope to see some more of your images here! Ciao, Paul | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Focusing with binoviewer and TV 102As far as we are aware, the TV102 will come to focus with the BF-30 and the Binoviewer provided that you are using the TV corrector/Barlow and a 1.25-inch diagonal. We do know, from our own experience with it, that it will not reach focus using a 2-inch diagonal. However, as this is a telescope phenomenon, I would suggest contacting TeleVue directly to get their advice on the proper configuration. We are not fully conversant with all the subtle requirements between all the telescope manufacturers but, we believe that, if you can get to focus with a standard eyepiece, then the Binoviewer should come to focus with the correct lens accessories. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
NEW 5 Year WarrantyJan. 2003 For the past six months, Coronado has been offering a 5 year extended warranty option on all previously purchased filters. Existing customers who already have an instrument can purchase this directly through Coronado.($275.00) This offer is applicable to all filters purchased previously and is open through September 2003. For new instruments effective March 2003 a five year warranty is part of the package.The warranty is NOT transferable and does not cover etalon decontacting or breakage nor damage to the blocking filter. Both of these items can be covered by our lifetime self insurance policy. Details available August 1 2003. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Truth about pinholes! Jan. 10 2003A customer brought to our attention the following statement that he found on a Solar Chat site and asked us to verify the information. " white light filter can have upwards of 50 x .5mm holes in its surface and all that will happen is that the background contrast will be diminished.There is not danger in using a solar filter with pinholes in it." The question of pinholes in white light Solar filters is one that is often raised and requires some clarification. Firstly, it is assumed that the term 'pinhole' refers to a very small defect in the coating. If the hole is large enough to create an image, then, obviously, it is a safety hazard. Small pinholes diffract the incident beam into a spherical wavefront. This emanating wavefront causes the light to be distributed across the image plane and, thereby, reduces the contrast. This effect will be enhanced by an increase in the number of pinholes. With sufficient number, the contrast will not be high enough to allow observation of detail. Another effect of the stray light from the pinholes is an effective reduction of the overall blocking of the filter. Most visual white light filters have an optical density of 5;- i.e. the residual transmittance is 1 x 10e-5 or 0.001%. This residual transmittance will increase with the quantity and size of the pinholes until the blocking of radiation becomes a hazard. For example, if a 100mm aperture filter had 50 pinholes, each 0.5mm diameter, the background from this would be 1.2 x 10e-3, which would be above the safety limit, particularly for infra-red radiation which is pernicious in that the eye will not normally notice any immediate effect, even though it may be damaging. The Coronado Better White Light Filter is guaranteed to be pinhole free. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
IN STOCKLarge aperture filters, dedicated telescopes and double stack systems are available as direct sales through Coronado. SolarMax 40 Filter sets & SolarMax 40 Telescopes are available only through dealers. SolarMax OTA's available from stock. This page is updated each time a dealer gives us an update. Once you have found a dealer with the product you are looking for click 'Dealers' from the menu bar across the top of the screen to find their contact information. OPT As of 11/6/05 Adapter Plates - Miscellaneous Binomites Binomite IIs BF10 Blocking Filters CAK Telescope Cemax Barlows Cemax 12mm Cemax 18mm Cemax 25mm Cemax Packages Cemax Pick Three Packages Coronado Hats Malta Mounts PST's PST Case PSM40 Doublestack Filter for PST SolarMax 40 Telescope Packages with BF10 Solarmax 40 Filter with BF5 Solarmax 40 Filter with BF10 Solarmax 60 Filter Solarmax 60 Filter with BF10 Solarmax 60 Filter with BF15 Solarmax 60 Telescope Package Solarmax 70 Telescope Package Solarmax 90 Filter with BF10 Solarmax 90 Filter with BF15 Solarmax 90 Telescope BF15 Solarmax 90 Telescope Doublstacked with BF30 Sol Ranger/Clamshell Combos for SolarMax 40 Telescopes SolRangers Zero Length Adapters Woodland Hills - last update 11/3/05 Solar Max 60 BF15 filter set--------------------2 Solar Max 40 BF10 filter set--------------------4 Solar Max 40 BF 05 filter set-------------------1 CAK 70 Telescope----------------------------3 Solar Max 60 Bf/10 Scope----------------------4 Solar Max 40 BF/10 scope---------------------7 Solar max 40 BF10 double stack Scope--1 PSM40 Double stack for PST---------------18 Solar Max 90 BF15/ .5>Angstrom Scope-1 Solar Max 90 BF 30 .7> Angstrom scope-1 Solar Max 90 BF 30. .5>Angstrom Scope-1 As of 11/8/05 La Maison de l'Astronomie P.L. inc. 8074 St-Hubert Montréal, Québec, Canada, H2R 2P3 (514) 279-0063 (514) 279-9628 courriel: maison.astro@bellnet.ca Site Web: www.maisonastronomie.ca Solar Hats....................................4 CeMax eyepiece kit......................1 12mm CeMax eyepiece.................1 PST's...........................................2 (10 more coming soon) PST CaK......................................Coming soon ADORAMA as of 11/8/05 CORONADO PST PERSONAL SOLAR TELESCOPE 8 CORONADO PST<.5 PERSONAL SOLAR TELESCP 2 CORONADO SOLARMAX 40 TELESCOPE W/BF-10 2 CORONADO SOLARMAX 60 TELESCOPE 1 As of 11/11/05 Phone: 229 467-2878 Fax: 229 467-2878 E-Mail: gphoto1@alltel.net Address: Abbeville Telescope Company, 351 West College St., Abbeville, Ga. 31001 1- Max scope 60 2-Maxscope 40 8- PST 4- Solarmax 40 TMAX 1- CMAX set 4 Binomite 2 5 Binomite 1 As of 11/11/05 Kansas Wind Power-W, 13569 214th Road, Holton, KS 66436 Phone: 785-364-4407, Fax: 785-364-5123 PST - 47 PST CaK - soon PST Cases Malta Mounts SM40 Filters for double stacking SM40 Filter / BF 10 SM40 Filter / BF15 SM60 Filter / BF10 SM60 Filter / BF15 SM90 Filter / BF10 SM90 Filter / BF15 SolarMax 60 Telescope Package 12x60 BinoMite II Cemax Eyepieces Cleaning Kits Hats Adapters: AP169 Vixen/Celestron 102 SM60 AP113 Short Tube 80 Celestron, Orion, Vixen SM40 AP185 Doublestack Adapter for SM40 AP102 TeleVue 76, Pronto SM40 As of 11/19/05 20/20 Telescopes and Binoculars 2 P.S.T Ha telescopes | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Blocking Filter SafetyJuly 22, 2003 A recent spate of Astromart postings indicate an interest in double stacking by acquiring front elements. Please be aware that Coronado blocking has always been and is 100 percent safe, however, design changes in elements of the filters means that NOT ALL BLOCKING FILTERS can be indiscriminately paired with any front cell unit. Please check with Coronado before attempting pairing with non factory supplied combinations. We'll be happy to help. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
VENUS TRANSITVenus Transit 2004 Sun-Earth Connection Education Forum On June 8th, 2004 a rare celestial event of historical scientific importance will occur when the silhouette of the planet Venus once again crosses the face of the Sun as seen from the Earth. This event, the transit of Venus, last occurred in 1882, so no one alive today has ever witnessed it. In celebration of the event, the Office of Space Science education and public outreach program will offer activities and resources that are suitable for use in classrooms and museums. Leading up to the actual transit event, everyone is invited to participate in Sun-Earth Day 2004-Venus Transit. The Web site http://sunearth.gsfc.nasa.gov/sunearthday has been developed to provide the resources and opportunities for participation. Students and teachers are invited to join NASA’s Sun-Earth Connection Education Forum (SECEF) and NASA’s Planet Quest Program [http://planetquest.jpl.nasa.gov/] to learn all about the transit of Venus during a live broadcast from NASA’s Jet Propulsion Laboratory. This interactive discussion will focus on what the transit can teach us about the search for planets beyond our solar system (over 100 have been discovered so far). Taped video segments and interviews will also cover how to watch the transit safely, the impact of past transits in history, and why Venus would be a deadly place to live. The event can be viewed as a Webcast for schools with high-speed Internet access, or a broadcast for those with satellite receivers on March 19th. For the actual transit event, join SECEF and San Francisco’s Exploratorium for a live Webcast on June 8, 2004. They will travel to Granada, Spain to visit the Sierra Nevada Observatory for a clear and unobstructed view of this amazing and rare event. Museums and community groups around the United States and the world will tune in as they explore the role of past transits in the history of astronomy and how the Venus transit was used to calculate the distance from the Earth to the Sun, called the Astronomical Unit (A.U.). The program will present cutting edge research on Sun-Venus and Sun-Earth interactions, and how NASA plans to use similar transits to detect extrasolar planets. During the time of the transit, professional and amateur astronomers all over the world will be waiting with sophisticated ground based telescopes as well as spacecraft that will view the transit in a myriad of wavelengths. A partnership with Telescopes In Education (TIE) and Virtual Telescopes In Education (VTIE) will provide images of the event. The transit will be viewed by a suite of solar observatories from Nova Scotia down to Uruguay. Images of the transit from these sites will be made available in near real time on the Venus Transit Web site so that students may make their own calculations of the A.U. and the size of our solar system. Data will be stored on the VTIE archives system allowing students to propose observing experiments, make observations, analyze their results, and publish their findings online. For American history buffs, school bands, and museum kiosks, John Philip Sousa’s Transit of Venus March, written in 1883, has been reperformed by the Virginia Grand Military Band. The audio music file and band scoring will be available at the Sun-Earth Day 2004 Web site. The Smithsonian Institution will be also featuring an exhibition of rare books related to the transit called “Chasing Venus” at the Museum of American History in Washington D.C. from March 2004 to April 2005. Co-lead Contact Information: · Formal Education: Elaine Lewis lewis@mail630.gsfc.nasa.gov · Informal Outreach: Sten Odenwald odenwald@mail630.gsfc.nasa.gov · Website/Multimedia: Troy Cline cline@mail630.gsfc.nasa.gov · Forum Coordinator: Karen Meyer karena@ssl.berkeley.edu | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
VENUS TRANSIT SUN EARTH CONNECTIONVenus Transit 2004 Sun-Earth Connection Education Forum On June 8th, 2004 a rare celestial event of historical scientific importance will occur when the silhouette of the planet Venus once again crosses the face of the Sun as seen from the Earth. This event, the transit of Venus, last occurred in 1882, so no one alive today has ever witnessed it. In celebration of the event, the Office of Space Science education and public outreach program will offer activities and resources that are suitable for use in classrooms and museums. Leading up to the actual transit event, everyone is invited to participate in Sun-Earth Day 2004-Venus Transit. The Web site http://sunearth.gsfc.nasa.gov/sunearthday has been developed to provide the resources and opportunities for participation. Students and teachers are invited to join NASA’s Sun-Earth Connection Education Forum (SECEF) and NASA’s Planet Quest Program [http://planetquest.jpl.nasa.gov/] to learn all about the transit of Venus during a live broadcast from NASA’s Jet Propulsion Laboratory. This interactive discussion will focus on what the transit can teach us about the search for planets beyond our solar system (over 100 have been discovered so far). Taped video segments and interviews will also cover how to watch the transit safely, the impact of past transits in history, and why Venus would be a deadly place to live. The event can be viewed as a Webcast for schools with high-speed Internet access, or a broadcast for those with satellite receivers on March 19th. For the actual transit event, join SECEF and San Francisco’s Exploratorium for a live Webcast on June 8, 2004. They will travel to Granada, Spain to visit the Sierra Nevada Observatory for a clear and unobstructed view of this amazing and rare event. Museums and community groups around the United States and the world will tune in as they explore the role of past transits in the history of astronomy and how the Venus transit was used to calculate the distance from the Earth to the Sun, called the Astronomical Unit (A.U.). The program will present cutting edge research on Sun-Venus and Sun-Earth interactions, and how NASA plans to use similar transits to detect extrasolar planets. During the time of the transit, professional and amateur astronomers all over the world will be waiting with sophisticated ground based telescopes as well as spacecraft that will view the transit in a myriad of wavelengths. A partnership with Telescopes In Education (TIE) and Virtual Telescopes In Education (VTIE) will provide images of the event. The transit will be viewed by a suite of solar observatories from Nova Scotia down to Uruguay. Images of the transit from these sites will be made available in near real time on the Venus Transit Web site so that students may make their own calculations of the A.U. and the size of our solar system. Data will be stored on the VTIE archives system allowing students to propose observing experiments, make observations, analyze their results, and publish their findings online. For American history buffs, school bands, and museum kiosks, John Philip Sousa’s Transit of Venus March, written in 1883, has been reperformed by the Virginia Grand Military Band. The audio music file and band scoring will be available at the Sun-Earth Day 2004 Web site. The Smithsonian Institution will be also featuring an exhibition of rare books related to the transit called “Chasing Venus” at the Museum of American History in Washington D.C. from March 2004 to April 2005. Co-lead Contact Information: · Formal Education: Elaine Lewis lewis@mail630.gsfc.nasa.gov · Informal Outreach: Sten Odenwald odenwald@mail630.gsfc.nasa.gov · Website/Multimedia: Troy Cline cline@mail630.gsfc.nasa.gov · Forum Coordinator: Karen Meyer karena@ssl.berkeley.edu | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Coronado's Top 10 MFAQQ. Why Coronado filters are so expensive compared to other solar filters? A. They aren’t. Coronado is the largest manufacturer of thermally stable sub-angstrom H-alpha filters. No one else even comes close to our prices and performance. Our 30+ years of experience in the optics industry led to the breakthrough that allows the average amateur astronomer the opportunity to view the sun in H-alpha for a fraction of the cost before we came into the market. White light filters and other, less expensive H-alpha filters, do not allow you anywhere near the same amount of detail, contrast, and resolution of finite surface features as a Coronado filter does. Q. How do I know which Blocking Filter (BF) I need, and what does it do? A. Coronado blocking filter (or BF) unit is in integral part of the whole filter system. Without this component you can’t even begin to see the sun. You choose a BF based on the focal length of your telescope. It is important that you get the right BF or you will not be able to see a full disk image. You will need this blocking filter in addition to the SolarMax filter If the focal length of you telescope is less than or equal to the following
All of our blocking filters, except the BF30, are housed in a 1.25” star-diagonal unit built according to a 45o folded design. The BF30 is built according to a 2” straight-through design. If your telescope is over 1000mm in focal length you can usually use a BF30. This 2” straight-through design of a blocking filter is also sometimes preferred for photography. Optically any blocking filter unit contains several filters, but its main job is to isolate the spectral peaks adjacent to H-alpha line. This allows a Coronado filter to show you the entire bandwidth of H-A and not just a portion of it. Q. What can I see with a Coronado filter? A. In a word, the chromosphere of the Sun. This includes flares, prominences, filaments, spiculae, faculae, CME’s, and a whole lot of other details. What you can’t see directly, but rather the effects of, are granulations and sunspots. The more you use your Coronado filter the better trained your eye will become. This training will result in a better ability to pick up finite detail. Q. What makes a Coronado filter safe for H-alpha viewing? A. It is the filtering design that guarantees the safety of the user. The first element in our SolarMaxTM unit is called an energy rejection filter (ERF). This specially coated glass rejects more than 90% of the total incoming light and 100% of all UV and IR light. The second part, the Fabry-Perot etalon, also acts as a known very narrow-band filter. If the etalon were to separate the transmission actually decreases. Our MaxScope series telescopes are designed as either a sealed unit, protected using a removable objective, or an additional ERF. Provided you follow proper safety procedures, Coronado recommends you establish a checklist for setting up your filter; a Coronado filter will pose no danger to you or your optics. Coronado now provides independent corroboration of the inherent safety of our filter systems. Please use the ‘site directory’ to access our ‘Safety Page’. Never use a solar filter from a manufacturer that does not provide this data. Q. Why should I buy a SolarMax 60 or SolarMax 90 if the SolarMax 40 has the same pass-band? A. Solar viewing has two very unique qualities that allow you to use a fairly small aperture and still resolve a detailed image. These are: an abundance of light and a total lack of light pollution. This makes the SolarMaxTM 40 a very portable, lightweight filter that performs to the same specs as our larger sized filters. However, its performance is still limited by its aperture. The SolarMaxTM 60 and -90 will, because of their better light gathering ability, always outperform a 40mm filter. You can’t beat the aperture! Will you ever be disappointed with the performance of a 40mm? No, not even when it’s seen in action side by side with its larger brothers. Will you always be more impressed with a 60mm or a 90mm SolarMaxTM? Yes. The best advice – buy what you can afford and you will not be left wanting. Q. What does “double stacking” do? A. You will see and hear this term a lot as you become more familiar with Coronado filters. Essentially what this means is placing one Fabry-Perot etalon sequentially with another in the optical path. As a result, the pass-band is reduced from the standard <0.7A to <0.5. This dramatically increases the viewing contrast, and the resolution of finite surface detail. Sounds simple, right? Unfortunately it isn’t quite that easy. The internal spacing or tuning of the two etalons must be matched in order to achieve the narrower pass-band. At this time an appropriate etalon matching should only be done by a Coronado technician. You can order a number of products delivered with the narrower pass-band. Everything from a “double-stacked” MaxScopeTM 40 to a custom built telescope. You can also send your filter back for matching to a second etalon. Give us a call for more details. Q. What is the best telescope to use a Coronado filter on? A. Ours! The MaxScopeTM series telescopes are the best telescopes to use for H-alpha solar observing. Everything from the focuser to the objective cell and the coating on the optics has been designed to maximize viewing contrast and minimize spurious reflections. Most nighttime scopes are optimized for the blue end of the spectrum. This causes the images at H-alpha line obtained with those scopes to loose contrast and resolution. Most any scope will work, but ours work best, there is no comparison. If you already own a SolarMaxTM and a blocking filter you can buy the corresponding size of MaxScopeTM to go with your filters. If you are looking to buy a filter and want to know the best telescope – buy the whole package! Q. What is the best filter for XYZ-telescope? A. Refractors: In most cases a refractor is your best option to use a SolarMax series filter on. The less optics the better. Depending on the focal length and aperture most refractors can use an appropriate SolarMax filter in combination with either BF10- or BF15-filter (more on these next) for visual and photographic work. We supply adaptor plates for nearly every type of refractor telescope. Reflectors and Other Optical Designs: Because of the large aperture and long focal lengths on most of these, it is best to use either a 60mm or 90mm SolarMax filter together with a BF30-filter. We can manufacture an adaptor plate for a given filter to fit almost any telescope up to 16”. Always feel free to contact a Coronado dealer or a Coronado rep to find out what is recommended for your specific telescope. Q. Does Coronado donate any filters? A. Yes, we have a limited number of filters that we donate to non-profit/educational organizations each year. To request one please contact Coronado for more details. While we wish it were possible, we cannot provide every group with a free filter but we do have discounts for said institutes. Q. “Hi, I am traveling through Tucson and will be by your store in 10 minutes. Can you set something up for me to see?” A. No. We are not trying to be mean or rude, but we don’t have a store. Our facilities are all for manufacturing and shipping our products. It is very hard for us to accommodate visitors without prior knowledge of their arrival. “Dropping in” disrupts the daily flow of operation. However, if you know you will be in Tucson in a week or two we would be delighted to have you come in for a view through our filters. Please call or email to set up a time that is convenient for both you and us. We cannot promise to have the exact set up you want to see but we will do our best. Please be punctual and understand that we cannot give you a full tour of the optics lab or polishing room for proprietary reasons. We look forward to seeing you. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SHIPPING POLICYSHIPPING POLICY The heart of every Coronado filter is an air spaced Fabry-Perot etalon. This is an exceptionally precise and fragile optic. The two etalon plates are optically contacted….no cement, wire, housing etc. holds them together. This is an essential element of the design. Over the past 6 years we have shipped thousands of these instruments and experience in shipping procedures has been our teacher. We contracted with a firm specialising in package design to develop the optimum packaging for shipping such delicate instruments. Essentially we “suspend” the etalon to minimise direct shock. It is our experience that the least amount of in-transit handling minimises the possibility of the etalon becoming decontacted during shipping and for this reason we insist on second day air as the only viable option. For customers outside of the USA we select the most expedient method of courier shipping. Apart from decontacting, the instrument and optics are relatively sturdy. We’ve had only two instances of optics being cracked or shattered in transit. Our decontacting rate runs around 1% of overall shipments and investigation of shipping methods surrounding a decontacted etalon invariably point to ground shipping. For this reason we insist that all returns for warranty work or matching be by second day air and we also insist that you return in original packaging. By this we mean the foam supports for the inside of the box and the factory supplied shipping case. For the PST this means the original foam dye cut housing for the PST. For the record, Styrofoam peanuts are useless for cushioning shock. We have always had a policy of shipping second day air and "old" dealers are well aware of that policy. With the advent of the PST the policy has been questioned and accordingly, we conducted numerous test shippings with the PST in its factory supplied packaging to determine if second day air was essential. We concluded that the packaging was sufficient to support the PST in ground shipments and, accordinly, changed our policy on this one instrument in July of 2005. We ask that you retain proof of shipping method with your copy of the warranty. Units other than the PST,shipped by ground transportation and decontacted on receipt will not be repaired under warranty. Although the box may not show any outward sign of damage, we urge you to open upon receipt and examine your instrument for obvious signs of physical damage. A decontacted etalon is not discernable by physical evaluation, it is only apparent when you observe the Sun. Should you have any questions about performance, contact our customer service department. They will advise you. Please contact customer service should you have any questions regarding this policy. Customer Service Coronado Inc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Meade to purchase CoronadoWe would like to inform you that Meade Instruments has signed an intent to purchase letter for Coronado Technology Group. The announcement was made early yesterday morning (10/21/04) at the Hands On the Sun Conference by Coronado majority shareholder, Gerry Hogan. Meade representatives were on hand to answer questions. Please use the link below to view the press release: http://finance.yahoo.com/q/h?s=MEAD Coronado is very exciting about joining Meade to further develop the solar observing market. The companies will be able to leverage off the combined technologies, manufacturing infrastructure, sales infrastructure and marketing concepts to bring new and innovative products to market efficiently. Coronado will remain in Tucson and the key personnel remain the same. There will be no obvious changes other than the ability to increase production and further the hobby of Solar observing. Our commitment to quality, innovation, safety and customer service remains the same. Since Oct.2003, Jordan Frazier, a shareholder, has been General Manager and he continues in that role. Founders, David Lunt & Gerry Hogan continue in a consulting role. Thank you for your support in getting Coronado where it is today. We look forward to an even brighter future. Gerry Hogan | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
2004 best of What's New AwardCoronado is excited to announce that our PST (Personal Solar Telescope) has been awarded a 2004 Best of What's New Award from Popular Science Magazine in the Aviation and Space category. Thousands of new products are reviewed annually for this award and the top 100 winners are awarded across 12 categories. We are delighted to be recognised as a leader in new technology. The December issue will be on newsstands Nov. 16th. http://www.popsci.com/popsci/bown/2004/aviation/article/0,22221,768291,00.html | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
PST A WINNERPST has been noted as the top of the list in S&T's HOT PRODUCTS 2005 listing (January 2005 issue). It has a rave review in Astronomy magazine (January 2005 issue) and Popular Science Magazine Best of What's new edition is on the news stands today, Nov. 16th. As the cofounder of Coronado and wife of David Lunt, I want to take the opportunity to say how proud I am of David's work and that of the whole Coronado team. With the PST in particular, I want to mention one of the "back room" guys:- Manny Serrano, design engineer, who has a unique ability to translate David's often esoteric concepts into hardware. Well done team Coronado. Gerry Hogan Coronado | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
HOTS UPDATEHANDS ON THE SUN 2005 SCHEDULE OF EVENTS Note that speaker times may changed based on weather & speaker’s schedules. This is current as of 9/8/05. We will leave a carpool board in the hotel lobby. Some of you may want to share rides. Thursday, October 6, 2005 6:30 p.m. open for registration details etc. Pima Community College, East Campus 8181 East Irvington Road Community Building 7:00 p.m Opening Speaker, Dr. Steele Hill, NASA - GSFC SOHO & The Sun Friday, October 7, 2005 Kitt Peak Field Trip – all day 7:45 - 8:15 a.m. – Meet at Coronado Offices , 1674 South Research Loop Ste. 436 , for coffee, juice and muffins. Parking available. If you pre-ordered lunch it will be available on Kitt Peak. If you did not, keep in mind that there are no facilities available on Kitt Peak and you will have to pack a lunch. Bring a sweater or light jacket. 8:15- 8:30 a.m. - Board vans, depart for Kitt Peak 4:00 p.m. - Board vans and depart for Coronado offices. 5:30 p.m.- Estimated time of arrival to Coronado offices. On your own Friday evening. There are several good restaurants in the vicinity of the hotel and we’ll give you a list. Saturday, October 8, 2005 7:30 - 8:00 a.m. – Pima Community College, East Campus, meet for coffee and juice. 8:15 a.m. - Opening Speaker, Rik Hill, University of Arizona, “What Am I Looking At?” 9:00 a.m. - Speaker, Paul Mortfield, Stanford University, “How an Amateur Solar Observer Can Contribute to Real Science”. 10:00 a.m. to 1:00 p.m. - Hiram Villarreal, John Adair, Tom Masterson, Paul Hyndman, Gary Palmer Observing and Imaging. Work through lunch. The college cafeteria closes at 1:00 p.m. There are no lunch spots in the immediate vicinity of the college. 1:00 p.m. – 2:00p.m – Speaker, Dr. Tony Phillips, “High Lights of Spaceweather.” Imaging continues. 4:30 P.M – Speaker, Gary Palmer, “Putting Together the Solar Puzzle”. 5:30 p.m. close for the day 7:30 p.m. – Fiesta at home of Gerry Hogan, Map will be provided . This is ~ ¾ mile from the hotel. An easy walk. Sunday, October 9, 2005 Pima Community College East Campus, Community Building 8:00 a.m. – Coffee and Juice 8:30 a.m Speaker Paul Hyndman, “What’s it all About, Alphie?” 9:30 a.m. – Imaging Sessions begin. Hiram Villarreal, John Adair, Tom Masterson, Paul Hyndman 11:30 – 1:00 p.m. On site al la carte lunch available by Pico de Gallo one of Tucson’s favourite authentic Sonoran food restaurants. (Written up in the NYT travel section as a “must taste” Tucson experience). Chicken, carne asada and veggie tacos and burritos. 2:30 p.m. - Round table imaging postmortems Hiram Villarreal, John Adair, Tom Masterson, Paul Hyndman 5:00 p.m. - Closing Speaker, David Levy 7:30 p.m. to 11:00 pm. - Dark Sky observing led by David Levy and Meade. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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