A friend tested my 12" GSO mirror tonight and indicated that it was approximately 1/7th wave with a strehl ratio of .86. He indicated that the turned edge kept the ratio from being higher. He noted some crescent shaped surface roughness primarily extending from the edge inward which he indicated was from incomplete polishing. Star tests show even concentric rings with no apparent astigmatism, however I have not had decent skies to get a better star test.
I Yam What I Yam!
