Celestron 11" on a CGX with focuser. The QHYCCD 5ii guide scope focused right in. However, I have had no success getting the ZWO to capture a shot that isn't grainy and tinged with red. I can get fairly sharp stars, but the graininess / noise(?) is extremely frustrating. Same results with SharpCap, NINA, and APT.
I hope someone has suggestions or references that would help ...
Boy, do I have suggestions. <smile>
I have both 183s and five years plus of experience. Sample image with the 183MC below. This is sincerely intended to be helpful. It may come across as harsh. But there are multiple problems here, and I wouldn't be doing you any favors to gloss things over. These go from least to most important.
One problem is that you're not looking at the right thing.
With a 183 you calibrate the lights with bias, flats, darks (or you'll see a ton of amp glow noise). Align, stack. This is true:
"Don't go by the visual appearance of a sub – short broadband subs with the 183 may look very thin, but when stacked, the final result will be fine."
https://www.cloudyni...hl= 183 tables
Next problem. That's a terrible camera for that scope. The tiny pixels want short and fast optics. I bought both 183s for my C8 RASA, 400mm, F2. That's what the camera works well with.
Image scale in arc sec per pixel generally should be between 1 and 2. For a beginner closer to 2 is better. Your image scale is 0.17. (focal length divided by 200. take the result and divide the pixel size by it.) Absolutely guaranteed to be a noisy mess. I tried the 183 on my 130mm F7, and got my least liked image on astrobin in quite some time. I've removed it.
Above all else. Truly, above all else. That's a bad scope for a novice to try to learn AP with. The wrong tool for the job. Like trying to learn to build fine furniture, while banging in nails with a crescent wrench. These experiences are absolutely standard, I have about a zillion of these quotes.
"I regret spending the first 6 months trying to learn imaging with an 8" Edge, with that scope it was a losing effort. Fortunately got a nice little refractor, and not only have the quality of my images improved but I'm actually enjoying the process of learning how to do it!"
"After months of learning and overcoming challenges <with the SCT>, and finally buying a shorter FL APO refractor, I really really really wish I had listened to everyone on here and started learning the imaging basics on THAT frac instead of on the SCT. Trust me"
Don't trust me, trust him. <smile>
My number one recommendation. it will work well with the camera. Or something similar, there are many good choices.
$389. It could easily save you a year of frustration and wasted effort. And a _lot_ of money, also. Reducer, off axis guider, sensitive guide camera... they'll cost way more than $389.
General considerations. No more than 480mm. No more than 10 pounds. No slower than F6.
"I have a C8 and this was the scope I learned AP on. It was a long, tough struggle and I have no good pictures to show for it. I could have easily saved a year by starting with a more image-friendly scope."
If you eventually want to image small galaxies with that scope, you'll reach your goal significantly faster/better/cheaper if you learn the ropes with something small. This is complicated and difficult, think months not weeks.
Edited by bobzeq25, 27 June 2022 - 01:38 PM.