Ok, I have been doing MOT and TOT 1/3 COC for about 45 minutes, here is where the 8" mirror stands from being a parabola. Zone 1 +.009 Zone 2 +.007 Zone 3 -.008 Zone 4 -.015 Zone 5 -.008 My actual readings are. 1-.026 2-.039 3-.039 4-.047 5-.069 Should I just continue with MOT, TOT standard 1/3 COC stroke? thanks bob-Denver,CO