ATM 8" F/7 Astigmatism

[david.a.stevens@gm.com]

This is the latest for my astigmatic mirror. I have measured across 1
diameter of my mirror ( diameter 1-3 ) and I take an arbitrary measurement
at about the 70% zone. I rotate the mirror 90 deg. and take another
measurement  on the 70% zone  ( diameter 2- 4 ). Dia. 1-3 is closer by .036
and the shadow is oblate sphere ( high edge,high center). Dia. 2-4 is still
oblate but closer to a sphere.

What to do???

A.) Do I keep polishing towards a sphere and hope the astig. will go away
??


B.)  Do I polish along the short diameter ( 1-3) TOT for 15 or 20 min. with
no tool rotation??


Any help is very much appreciated,

Dave