Originally Posted by Rod Kaufman
I always take interest when someone wave-rates mirrors from different makers and when searching the web, I found a source of note. Alan Rahill runs the clear sky clock which a very valuable source of information of sky conditions in many locations and it turns out he's also a mirror maker as well.
Best he's tested were Nova and Zambuto with the latter at better than 1/10 wave. Swayze at 1/5 wave "with micro-ripples". Galaxy at 1/3 wave. See link:
http://www.lcas-astronomy.org/articles/display.php?filename=quality_of_todays_newtonian_optics&category=general
Thanks for posting that link Rod......I was pleasantly surprised to see what was said about Nova since my 20" f/5 is a Nova from back in the day when Obsession used Nova mirrors. Over the years I had come to the realization that I likely have an exceptionally good one. It star tests as a system very well and on those nights where the moon, planets, stars and atmosphere all seem to align and the mirror fully equalizes, the views and the power it will take seems almost unlimited ie crisp clear views upto 1000x. They don't happen often but when they do the Nova seems to rise to the occasion for some Ohhhh WOW experiences.
Sadly as I recall from back then Obsession eventually stopped using Nova due to some consistency issues. I don't believe they have offered any mirrors commercially in a few years....just coating.