Quote:
Originally Posted by codemonkey
Hmm. That looks like bad astigmatism to me. No direct experience, but from the research I did when trying to solve my own issues, bad astig will cause in focus stars to look like crosses. You can confirm by watching the stars as they go either side of focus... if they elongate in different directions on either side of focus it's astig.
Also looks like there's some residual tilt / collimation going on -- some of the stars are bigger than others.
As for me, I don't even remember what spacing I'm using any more. I tried so many variations with multiple correctors on multiple cameras... think I might be around 57-58mm with the Paracorr I?
The hardest part about this is isolating all the contributing factors, thus why I suggested first confirming (without the corrector) that the best stars are in the center of the frame. I think that confirms primary / focuser alignment.
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Yeah the astigmatism is awful...I'll have to chuck it on the mount next clear night and check visually.
I never expected it to be easy to tame a fast newt, but astigmatism is a wildcard I hadn't hoped for.