Quote:
Originally Posted by Stefan Buda
So you are using the two focusing methods in two different orientations of the scope (different parts of the sky). Are you sure there's nothing in the optical train that can shift/move when you go from one part of the sky to the other?
|
I don’t think it’s movement when slewing around. In that example I gave, critical focus with HFD was made, then I skewed to Rigil Kent, saw the mask focus was way off, went back to my target and focus was unchanged. So between slewing to, and back from, Rigil Kent, the telescope remained in focus although the check of the mask while on Rigil suggested that (if the mask was to be trusted) it was out of focus, FWHM after returning to my target was excellent.