Posted by Roy Hughes at 18:15 on 2012 Mar 31
It may not be useful, but here’s my thoughts.1. It looks like a very out of focus star as seen visually in my Celestron C8.2. It’s off centre.Have you got an artificial star just outside the field of view, and rather closer than infinity?Maybe a chrome screw on the tube. An over long screw securing the corrector plate might do it, on my old C8 they poke though the tube and just stick out on the inside.Roy