One of the members who frequents the binoviewer forum.....eddgie.......has a theory that we are effecting our diffraction limited optics by hanging longer and longer equipment on the back ends of the moving mirror scopes. Stuff like 2 inch mirror diagonals and Binoviewers......introducing SA. This could equate to the bad views people claim to get. I view with my C8 and binoviewers 100 percent of time. Using the stock visual back and 1-1/4 prism diagonal stars looked a little bloated and duller. Not as sharp. I shortened the optical path on the back end by using a short SCT adapter and a T2 threaded Baader diagonal and coupled the binoviewer to the diagonal with a small adapter as opposed to the 35mm long eyepiece adapter. I chopped 136mm out of the focal length. The views with this shorter set up are sharp as a tack and the stars are no longer bloated looking. Focus just snaps in. Some of these tiny aperture apo versus C8 contests may not have the C8 set up for optimal viewing. They might be using long mirror diagonals which optical path longer and not where it was designed to be.
A properly collimated C8 with a 1-1/4 prism diagonal (optimal designed length) should be able to take a 5 inch APO’s lunch money.
Edited by sonny.barile, 28 January 2018 - 05:08 PM.