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  1. Weather in eastern Germany was quite nice. At first contact it was very clear. Some steady moments during the eclips provided some very detailed view of the edge of the moon and said craterlets, cool! The two groups of sun spots were prominent as was the very granular surface of the sun. I do have an EMC solar foil front filter and find the contrast lacking due to stray light, that is very evident when some wind hits the foil. The movement of the foil is clearly seen in brightness fluctuation over the whole view. I wonder if a Herschel wedge will provide better contrast
  2. In fact this summer mid September during vacation. Not only was this at a dark sky area, but one night was blessed with incredible stable atmosphere. Jupiter and Saturn at 15° alt where proof of that. I observed Mars with the 100DC and bino/ADC and it was the best view I had in any scope yet. That night really showed, how much influence atmosphere has on the detail. The girlfriend was mighty impressed, not only of Saturn being super sharp and stable (which is her favorite planet), but Mars put up a tremendous show she revealed later. CS
  3. Oh there are some: putting the counterweight on my AP1100 already mounted on the Losmandy HD tripod... I felt the mount tilting and called for the girlffried holding everything. Another instance is when putting the large 185 frac on the AP1100 with or without counterweights on the shaft: If the tripod is oriented, that one leg is not along the counterweight shaft, the whole assembly can easily be tilted and topple over when I put the scope on it in park position 3. Mounting the large apo always gives me the creeps, regardless of the mount
  4. Wait, since when is there a 2nd edition??
  5. I quickly ordered the 1.6 and 2.4 last week from local vendor. I am missing the 2.0 and after some calls got it back ordered for delivery later this week or early next week. Fingers pressed this works out. I used the eyepieces last night in my Tak100. The 3.4 and 2.4 are almost something "common" when it comes to Jupiter or Saturn. Especially Saturn can take so much magnification. I used the 1.6mm on a beautiful star test, and will use it in the future for double stars. edit: I woke up at 4 a.m. and observed Mars with the 3.4 and 2.4.... Seeing was not the best despite meteoblue predicting best 5/5 conditions CS
  6. Hi Mark, The 35mm Eudiascopic is really the finder pair or for lower mag only. During the last days I used my TEC140, GPC1.7 for some cluster viewing, but with my 25mm Cel X-cels, because the 35mm need just a little more inward focus . For the 35 I would have to switch to the 2.6 GPC, pratically rendering the longer fl compared to the 25mm useless. This is for the TEC140. Nonetheless they are nice with the TAK or the CFF. Very sharp - obviously also due to the low magnification. For higher powers I use Morpheus 17.5 and 12.5, followed by 9 and 7mm Delites. The laast three get most usage during this planetary season in any of my scopes, combined with 1.7. Sometimes I also experiment w/o GPC in the CFF. I will add another 5mm Delite to complete the pairs in my collection CS
  7. Hi Mike, I was reading telescope-optics.net on this topic. You may find the article interesting: https://www.telescope-optics.net/induced.htm#systems More specifically certain parameters are defined. According to the model those will align on good seeing conditions for larger aperture to being more effective and smaller during bad or worse conditions. From what I understood this is due to coherence length r0 and turbulence structure constant cn^2. In summary it seems, that the atmosphere can in fact create cells were small diameter optics <=10cm are way less affected than larger scopes. However, the model does have its limitations as the last paragraph states: The standard Kolmogorov model of turbulence uses certain assumptions which are not strictly met in field conditions. This can significantly affect its accuracy. In general, the actual error is smaller than what the model predicts, as outlined in more details on the next page.
  8. The more expensive version of the Gutekunst is offered with a barlow and has a larger diameter (38 vs 28mm), to offer a better large field experience. For planetary and even 1.25" eyepieces I don't see vignetting. As I have written here, I didn't barlow the ZWO ADC when I had it. This was because I didn't know. With the Gutekunst ADC Mr. Gutekunst also recommends barlowing for f<10. However, I have not seen a better performance with my scopes using them at their native f/6.8 to f/9. So experience may vary. I think Gutekunst is also recommending this for the last tiny bit super optimal performance. As BGazing writes using a barlow on the ZWO will reduce astigmatism. However, Gutekunst recommends the barlow to reduce chromic abberations by the prisms. No native astigmatism here. BTW John, I can use the LZOS 130 f/9 (I think you have the same tube version with 2.5" focuser from FT?) and I can reach focus with ADC/diagonal/GPC1.25/bino combination. No barlowing needed when I use the GPC, because this adds enough back focus. Granted, the Gutekunst eats up 48mm optical path, compared to the smaller ZWO unit as pictured above ~ 30mm giving a little more room for focusing. Imho the bubble level is not necessary and rough tweaking of the orientation is enough. It gets more complicated in mirror systems like newtons though. There neither bubble level nor pendulum will work.
  9. I would say, that the benefit decreases with increasing altitude of the planets :D. Larger apperture users may notice this easier because they can magnify more and retain brightness of the object and thus the AD effect. For the low heights the planets are currently, I don't want to observe without one. For me it is a similar gain in viewing quality as the switch from mono to bino. Which I also don't want to miss during then planetary season. And just as mono vs. bino discussion, you have to try it for yourself
  10. Nice references! Interestingly in the S&T link there is reference to AD and seeing. See the lowest grafic where AD and influence of poor and good seeing are plotted against star image size. This showes, that even in good seeing objects below 60° will have an added effect due to AD. Mr. Gutekunst who is the designes and manufactures the ADC, also suggested to use the ADC even for objects above 50-60°. Of course the graph also tells, that in bad seeing situations ADC's won't help and seeing dominates the image or viewing quality. On the thought about smaller scopes giving better views than larger in bad seeing the S&T link clearly says, that this is not the case. I had a thought experiment: Consider a 100mm scope, an air mass with height of 1000m, eddy size of 300x300x300mm³ and altitude straight above at 90°. Could you calculate the statistical chance for non-overlapping eddies on a circle with 100mm diameter projected on the scope. The same for a larger scope, smaller/larger eddys and for different altitudes with its increased airmass.
  11. Nice report BG :). I also observed Jupiter and Saturn last night with the TEC140 and ADC/bino. I used the 1.7 GPC with which I come to focus nicely. However for magnification I also tried the 2.6 GPC. This let to some extrafocal blueish tint... The focused image was nice though. Jupiter put up quite a show. Io was moving in front of the Jovian disc followed by the moons shadow. Remarkably, the disc of Io was very well defined against the planet during the first 20min after the beginning of the transit. Did I make out surface details on the moon? Don't know. But the disc definitly seemed to have some coloration compared to is typical disc-like appearance when not in transit. Maybe the lighter background of Jupiter provides some less drastic constrast between the surface of the moon and the Jovian disc. Because the moons appear as homogenous discs (although with well defined magnitude differences and a little bit of different coloration). Unfortunately, I wasn't able to observe the appearing GRS, because I was too tired from the night before and conditions were becoming worse. Nontheless, a beautiful observation.
  12. Just imho bubble level is not necessary. I think some degree mismatch is ok and may not be visible visually. Maybe when doing AP? And the bubble level needs careful alignment on the device during production
  13. You could be right there BG. The Gutekunst does not have this issue. Strehl including astigmatism and tilt 0.998.... BTW: Some were arguing the two levers of the ZWO unit. There is an ADC from Pierro Astro (Version 3) which has only one knob for tuning the ADC, so somewhat less "complicated", of course its more than the ZWO unit: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p5992_Pierro-Astro-ADC-MK3-Atmospheric-Dispersion-Corrector-with-T2-connection.html . I would like to try out the ZWO and Pierro Astro device again, after I gained some knowledge in this field in the recent months. best regards
  14. I had another pleasant last night. I used my TEC140 with the ADC/mirror diagonal/1.7GPC/bino and 7, 9 and 12.5mm eyepieces. Conditions were not sogood during the beginning of the session at around 10-10:30 p.m. Jupiter was around 5-7° altitude. The problem was not AD but the atmosphere. It was like looking through a waterfall ;). Still, detail was visible: the GRS and clouds around it, the bands north and south of the equator, etc. It greatly improved later on towards the meridian. Jupiter's moons were tight defined spheres discs, with different size and magnitude. I did another test: I switched to view without ADC and what is easily noticeable is, that the moons are not defined spheres discs anymore, but washed out/elongated due to the AD. Also details on Jupiter were less defined and less sharp. Less sharpness was also very prevalent on Saturn without ADC. That being said, an ADC will help you in good nights to make (some) extra detail/features visible, but will not help when the jet stream or local seeing is just not there :).
  15. No I had no barlows or PM back then. I just measured the height of the quick changer: 10mm. Add to that 5mm from the dovetail/bayonette part with T2 thread you get 15mm. However, in my bino the dovetail is similar to the one in Baaders Mark V/Maxbright II, which may reduce the optical path length. The Maxbright also comes with an T2 adapter to directly thread it on a male T2 adapter (like on their T2 diagonals).
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