Quote:
Originally Posted by Paul Haese
Hi Jim,
I reckon you have to buy the best one you can afford at the time. If you can afford one of the good ones then go for that. I like my GSO 12" and it has very good optics despite some detractors here saying there must be a problem because I have not done much imaging with it. My agenda is to get my automation sorted on my smaller scope first before sorting it on my RC12. After which people will see more images coming from my RC12.
My only comments with the GSO gear is the focusor is not up to par, you have consider buying a top grade focusor for these scopes. Feather Touch or Moonlite and nothing of lesser quality. The cost of these focusors is significant and that will add to the overall cost of the project. You want to be able to use focusmax with the focusor down the line too as focusing RC's is a pain by eye. The 12" has a ali tube which should have been truss design. I don't know if GSO plan on a truss system as I am seeing carbon fibre tubes being mentioned at Andrews, but the current design can be seen as problematic.
The Meade is not an RC design. It is something entirely different and has its own issues. Dew as you would know can be a problem with a large corrector. Orion optics gear is good, but remember Mike Sidonio has a 12" Newtonian. Not an RC. If might be something you might want to consider if you want to do more wide field imaging and allows for some narrower field imaging.
Deep sky intruments also make an RC, as well as Officina Stellare. These are all cost orientated, but excellent telescopes made for doing research grade work as well as excellent imaging.
I would also consider forgetting the imaging with just a DSLR. To really image at any RC's potential you really need a mono camera for such a scope. A full frame sensor is what you should be looking for here or the 16803 sensor which is like two full frames put together or you could go with the 6303 sensor which is perfect for mosaic work. I am using an STL11000M on the RC12 if that give you any indication, and my NGC253 image is a crop as pointing was quite a bit off.
However, you choose try to spend a bit of time thinking about the issues. What mount are you planning on using? You will need a beast of a mount to make imaging with a long focal length worth undertaking. You should consider buying an second hand PME on Astromart and shipping it out here. I do know of someone here that is selling their PME but they want 12k for it. Its a good mount with little use. A PME is really what you want with a 16" RC. It will be a huge scope and very heavy.
Best of luck finding the scope you want. Feel free to ask me any more questions that you might think pertinent.
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Mate, thanks for reply. I appreciate it. I have a new Titan 50 that currently swings a C14 'fastar' and a Gstar EX2 video cam. Guiding (again by video) if need be, is through a Konus 5" F8 g/scope. Sky X Pro controls the lot.
Not sure of the weight of the GSO 16" RC. Some say it's around 38kgs, so that mount should handle that mass if I go that way. The tube rings of the GSO scopes are too thin to my liking and had to get a set of rings from Joe at Parallax. The GSO RC 16" may have to be the same.
I agree. ALL RC's should be trussed but in my case being out in the sticks, we too get dew and dust. Whereby a full tube is fare better. I do see the Mallin 12" RC's are ribbed inside and I have not seen others over 10" that are ribbed. The GSO 16" tube from what I've been told, is Ali or metal. This runs parallel to what a mate of mine said, a few weeks ago from his trip back from Taiwan, saying they and the Chinese have problems making good quality, CF tubes.
Perhaps those with ribbed reflecting scope tubes can wade in here and tell us what they have noticed, over non-ribbed internal telescope tubes?
As for a CCD camera, I've checked out SBIG, FLI and Apogee and like all things in life, it comes down to $$$'s and priorities. So until I win Lotto, I'll do what I can with what I've got.
As for those focusers you mentioned, I'm going to check them out. While Crayfords are nice looking and neat, they may not be the way to go on an RC.
Maybe someone else who has an RC, can wade in here and give us all a 'heads-up' on critical focusing of the RC?
Unlike a full classical cassergrain like have which has a late '90's AP 2.73" focuser, focusing is a breeze. Any other system that has a tight foci, can be a real PITA, particularly with CCD and Digital.
So I'll keep you posted mate, as to my journey through the heather and avoid selecting a Scot Thistle.
Jim