michael.h.f.wilkinson

Very nice indeed

One thing I really like is how collimation is rock solid. I got this image of Jupiter after about 20 years of scope usage, without collimating once (I check every time, but only recently did I give it a tweak)

Thanks! I am thinking of getting a C11, but they can take this scope out of my cold dead hands. It is a brilliant, portable piece of kit

I took this with my Celestron C8 (25 years old in two weeks), on a Vixen Great Polaris mount with an ASI183MC camera. I used no Barlow, but used some a flip mirror, an R&P focuser, and extension tubes so the scope focuses at F/12-F/13, which is near optimal for the pixel size.

Here is the animated gif I made of last night's data Olympus Mons is also nicely visible, which is a first for me

Managed quite a sequence of Mars images, using the C8 with ASI183MC camera. Seeing got progressively better, until clouds came in 21:42 22:24 23:02 23:36 00:09 All are stacks of 1,500 frames out of 10,000, stacked in AS!3, wavelets in Registax. Very pleased with the amount of detail I managed to get out. Will make a little animation later

First results. Will grab more data later C8 with ASI183MC, stack of 1,500 out of 10,000. Stacked with AS!3, wavelets in Registax 6

Binoculars are my weapon of choice for M33, either that or my 80 mm refractor at 15.5x (Nagler 31T5) or 22x (Nagler 22T4). I am hoping to get a chance with my Meade SN6 6" F/5 Schmidt-Newton, which should be ideal (3.2 deg true field of view with the Nagler 31T5).

I find globulars like M13 have enough surface brightness to have a go at when the moon is out. Alternatively, I go for planetary nebulae or other emission nebulae with narrow-band filters (the Optolong L-eNhance is my current favourite)

Best of luck. The forecast here is abysmal for the coming week at least

The night was unexpectedly clear, so I set up the C8 and got what I think is my best Mars image so far. Still processing some other SER files, and clouds have now rushed in, so the fun has stopped, but still very pleased with this image. Stack of 2,500 out of 10,000. Stacked with AS!3 and wavelet sharpened in Registax.

I have quite strong astigmatism, and must wear glasses while observing. I have found that for me any eyepiece with an eye relief of 16 mm or more works, and anything between 18 and 20 mm works well. This means that the 25 mm Plössls supplied with many scopes are fine. The 10 mm eyepieces supplied with many scopes aren't at all. Very long focal length Plössls become uncomfortable due to much too long eye relief, although that can be solved by good eye cups. The TMB planetary EPs and their clones are very affordable, and fine for glass wearers. Among the clones the TS HR Planetaries get good reviews. The Vixen LV, NLV, and SLVs are more expensive, but clearly better. These can come up second-hand from time to time. At the high end there are the superb Tele-Vue Delos and Delite EPs, and Pentax XWs.

Yet in practice, a factor of two is not really needed, or is even detrimental, especially because of the effective dithering that takes place (unless your tracking and seeing are both perfect).

I actually used the ASI224MC on a C8, and got much better results with the 2x Meade TeleXtender (tele-centric Barlow), or perhaps the 2.5x TV PowerMate than I could ever get with the 3x TeleXtender. I only ever used the 3x on older chips with much bigger pixels. I now use an ASI183MC (same pixel size as ASI178) for planetary and lunar (and even deep sky), but for planetary I only need a tiny region of interest. Here too, I tried the 2x TeleXtender and got much poorer results than without (but with flip mirror and R&P focuser in place, in which case the C8 is working roughly at F/12). The ASI178MC can also be used for planetary as OSC option.

Very nice work indeed!

I have a 2" Orion (USA) branded on, but I think it is made by William Optics. At low magnification, no diffraction spikes are visible, although the out-of-focus appearance of stars is weird. At higher magnification, I do see issues with diffraction spikes. I really only use it for wide-field observing with my APM 80mm F/6, so don't mind. I am not sure an Amici prism without diffraction spikes can be designed. I have a few cheaper Amici prisms I used for my giant finder, and they are also only really for use at low magnification

I also have an older Carl Zeiss 85 mm F/1.4 (Contax mount), but to date have had better results with the Sigma

The thing is that especially for those CMOS sensors optimized for planetary imaging, read noise is so low it hardly affects the image. Other sources are orders of magnitude larger, especially sky background in Bortle 4 or 5 skies (that is considerably larger than even the dark current in my non-cooled ASI183MC). Back to the original image: Really nice result, inspitrational, even. I am now curious what my ASI183MC with Optolong L-eNhance filter might do combined with my Sigma 50-100mm F/1.8 zoom, which really surprised me in its performance at F/1.8 on comet NEOWISE. Even with the larger sensor of the EOS 80D stars were pretty good in the corners. Might be worth having a go.

Glad the issue was resolved. As far as I know these are made by Vixen, and look identical to the Vixen ARK 20x80mm bins of a former PhD student of mine. I also briefly had the 16x80 version, but the maximum IPD was 72 mm which was just shy of my 73 mm IPD. I didn't notice this in the 20x80s, which gave beautiful sharp images, but with the larger exit pupil of the 16x80s it was a bit of an issue. I now have the Helios LightQuest 16x80, which go to 74 mm IPD, so I have room to spare.

There are wider ones. The TMB Paragon 40mm had 68 deg FOV (clones are the TS Paragon and the Skywatcher Aero). There is also the Meade S5000 40mm SWA (or its MaxVision/ES clones) at 68 deg FOV. I have a Vixen LVW 42 at 65 deg FOV, and the Panoptic 41 mm is also 68 deg. These offer the widest true FOV in a 2" barrel EP. this is why 50 mm EPs generally have a smaller apparent FOV. If you can get your hands on a TMB Paragon 40mm I would pounce on it, as it is very good, comparatively light, and extremely comfortable.

Really nice!

Finally got round to processing the other batch of data I got on September 19. This concerned 302 30s exposures with the modded Canon 550D and 200 mm F/2.8 L lens stopped down with a step-down ring to F/3.5 on my EQ3-2 mount. This was clicking away with an interval timer while my ASI183MC was gathering M27 data on the Meade SN6. I stacked the results in APP, and tweaked a little bit in Gimp. No filters used, and focus was apparently nudged slightly off, which caused red halos round stars. Still, I am quite happy how much detail was captured in the nebula itself, given my Bortle 4-5 skies. Should try this combination again, and lock focus properly.

+1 for the ASI224MC. I had a lot of fun with it. I now have the ASI183MC, which handles both planetary and DSO imaging well, but that is considerably more expensive

That is superb. Should really get myself a C11 or similar scope

That is very nice indeed