in particular the section under „Image brightness“
One other item on the 20x65 ED. I own a pair myself and love them. I was wondering if the units you tested had the threaded eyepieces for filter use? I noticed you measured the eye-relief at 11.5mm, so wanted to give an update.
Before I bought mine I had talked to Kevin about this, because I wear glasses for observing. He told me they no longer use those threaded eyepieces, and sure enough mine do not have them. Unfortunately I don’t have a Dynameter, but I can attest that the eye relief is now much closer to the stated 18mm, as I have no problem seeing the entire 65* AFOV with my glasses on. 15mm is about my minimum for this so it’s at least up to that now for usable ER, and seems even a bit more to me.