Quote:Hi All, I was looking at a primary that had an RTA of 0.23 . What does this tell me about the quality of the mirror? Thanks In advance for the inputs
XT10 classic with premium optics Tri-knob CR2 focuser
Catseye + Glatter collimation tools
StarBlast 4.5" & 6"
Round Table Platform
Quote:Thanks, It is an Ed Stevens Mirror with a Strehl of .991, RTA of 0.23 and wavefront of <1/20. Another mirror I am looking at is Strehl 0.993, RTA of 0.73, and wavefront of <1/20. Is there realistically a difference between the two (assuming you can believe the ratings).