atlas eqg w/ 11" edge hd for ap?
Posted 06 April 2013 - 11:23 AM
Posted 06 April 2013 - 12:55 PM
Suggestion for you, go to astrobin and do an equipment search. You'll find people who have done what you're trying to do and get truth data from people who have actually imaged with it.
But, I really don't think you're going to get good unguided photos anywhere near your requirement of 2 minutes. People tend to exaggerate what they're able to accomplish with the low-end mounts in my experience. Or, they are very experienced imagers who understand a particular limitation and work around it to effectively employ it when others can't.
For experience sake, I tried a 10" Meade SCT on a CGEM. It was not fun.
As you'll find most imagers say, buy the best mount you can afford.
Posted 07 April 2013 - 11:29 AM
Now if you want to try HyperStar imaging, then you would have a much better chance at success. But it will cost you more. The Celestron focal reducer could help, but it will still be difficult and will cost you about $600.
The Atlas is not underrated at all. It's just that some people push its limits and fiddle and tweak it until it sort of works. But you would be hard pressed to find many people successfully using a C11 at native focal length for AP on the Atlas. Not impossible, just highly difficult.
Also, if you are not guiding, then you are wasting your time on this mount (on just about any mount with an SCT for that matter).
Posted 07 April 2013 - 11:48 AM
I am actually amazed that you had success with you 8 inch SCT without guiding. Off axis guiding or Hyperstar is the best way to have consistent results with an SCT.
Posted 07 April 2013 - 12:04 PM
There are big defferences in getting something to work once, work all night(or part of it), work all night every night. (It seems you're already experiencing this) Imaging is about 'the whole kit' working reliably and repeatably. Large apeture and long focal length imaging imaging require a significant imaging mount. You can dial down apeture and focal length and the requirements loosen up 'a little'. So I'd recommend for imaging sticking with the 8" cat and reducing it with the f/6.3, and then getting something to autoguide with like the Orion Miniguider. So I also recommend to start out with using a setup that uses guiding, and autoguide. It can only help, even with shorter exposures.
Posted 10 April 2013 - 04:06 PM
Posted 10 April 2013 - 07:23 PM
If you're getting into AP and think it'll be a long term thing, get a good mount. It's the best investment in the hobby you can make.
Good luck with the C11!
Posted 11 April 2013 - 09:13 AM
Posted 11 April 2013 - 09:23 AM
I'll make one suggestion, hope you don't mind...
Keep your 11" edge for visual and buy yourself 80mm f/6 APO for AP. You'll be amazed...
And please do guide, why would anyone want to do unguided imaging? Unless you have high end mount, of course...
Posted 11 April 2013 - 09:45 AM
note: images are single exposures of about 2 minutes each and prossesed and cropped in digital photo profesional.
Posted 11 April 2013 - 03:48 PM
Posted 12 April 2013 - 05:30 PM
Off axis guiding or Hyperstar is the best way to have consistent results with an SCT.
I would add OAG + reducer.
ONAG is also possible on classical SCT. ONAG = On Axis guider. There is a semi-reflextive diagonnal which reflect the visible spectrum at 90°, to the main sensor, while the Ir emission passes through the glass, going to the guiding sensor. This require a lot of backfocus, so almost compatible with SCT.
On edge SCT, le backfocus is 146mm (same with or without reducter). The ONAG might be too long, depending on your camera.
If you really want to do some imaging with the C11 on the Atlas, at least an OAG + a reducer is needed.
Also big pixels are required: about 15µ pixels without reducer (or 7.5µ in bin 2 mode)and 9µ pixels with the x0.7 reducer which already gives about 1" per pixel.
If still not good enough, then you may either try the Active Optics (SXV AO, Sbig AO, Orion AO...) or upgrade the mount.
Posted 14 April 2013 - 07:50 AM
Posted 14 April 2013 - 09:19 AM
Posted 14 April 2013 - 09:56 AM