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I just checked out the TS UNC 10" f/4 Newtonian.
using Dave Keller's Newt for windows 3.1.
(Luckily I have a Win XP laptop to use the program because it won't run on a modern 64 bit operating system.)
I found that even that needs a larger focuser than a 2'"
There was 75% vignetting of the rays at the front aperture & the focuser.
I also notice that other 10" f4 systems use a 3" or larger focuser.
My 2" RCC1 coma corrector goes deep inside the focuser so even that would cause vignetting.
I need to use that RCC1 so that I can use my QHY9 + filter wheel + OAG = 70mm of back focus.
What is going on?
cheers
Allan
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