So, over the past few months I quietly disassembled and parted out my 20" reflector, which included selling the primary mirror. This was mainly due to the scope's large size being unfit for transporting to dark skies or use in my backyard. Today the buyer of the mirror got test results back from an optical tester, and the results were... shocking.
The mirror is hyperbolic and astigmatic, by about 2.5 waves. This was a complete surprise to me, since I'd used it in a scope for about six months and apart from some relatively slight fuzziness at high magnifications and some weird ghosting effects I'd thought it was fine. Even when it didn't perform so well, I blamed it on thermals or occasionally bad seeing. I'd come quite close to buying a new mirror cell and cooling fans for it, thinking that might solve the issue. I'm not going to blame the maker of the mirror since he'd said himself he didn't remember how it had tested, and it was very generous of him to give it to me.
A while back, someone commented on my lack of structural knowledge about hardwoods, and questioned how I could be selling custom scopes when I lacked understanding of this relatively basic information. Granted, it was delivered in a rather insulting manner, but the point was valid and I foolishly dismissed it. Well, he was right. I don't really know all that much, and today proves that when it comes to star testing I've got a lot to learn. I really shouldn't have been trying to sell custom-built scopes without some more engineering and optical testing knowledge. But I'm a teenager and I wanted money and had too much pride (and definitely some narcissism) so I just went ahead and ignored all of my detractors.
I would like to apologize for my arrogance and ignorance on this forum and on CN in general (as well as Reddit) and I hope to alleviate it in the future.
Clear skies everyone!
Edited by Augustus, 18 June 2019 - 09:49 PM.