Cheers folks. The SN-8 goes alright. If you buy one you MUST get a new focuser. The rack and pinion is a shocker. It's a real pain to focus at f/4. It causes me a lot of grief. A good crayford with 10:1 microfocuser would be a dream. The design of the SN reduces coma, so it is less than for a standard newtonian of the same focal length. Noticeable coma still exists at the edge of frame. I'm experimenting with an MPCC Coma corrector which seems to do the trick.
With a 10% SN I wouldn't mount it on an LXD-75. I feel a 10" would require an Atlas (EQ-6) or better if you're also mounting a guidescope. There's a smidgeon (about 1cm, maybe less) of in-focus left when you put a Canon camera at prime-focus. Always enough room to add filters, etc. and stay in focus, but there's not enough room to insert an off-axis guider.
Hope this helps.
Quote:
Originally Posted by [1ponders]
You know I've often thought about getting a 10" SN Bill. You've just about got me convinced. 
Any back focus issues with the canon? Any need for field flatteners or does the corrector plate do the job well? |
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