Re: ATM Hogging Out -making flats????

[Anthony Stillman <atmer@flash.net>]

Here's and idea.  Someone with money could buy a sheet of that liquid
crystal pressure sensitive color changing film that Bill T. noted to the
list a while back.  <http://www.fuji-prescale.com/pressurex.html>  Then,
sticking it to the face of a flat clear backed mirror blank, a series of
photos could be taken through the blank while it sits on a flat tool.  Each
photo would show a different offset between the centers of the blank and
tool.  These images could then be used to qualitate what a simple Finite
Element Analysis could only quantitate.

Incidently, flipping between MOT and TOT (1/3 W or C/C) won't make the
mirror flat.  Rather, it will reduce the third order (primary) spherical
abberation (power) to the point where the fifth, and higher order spherical
abberations (ring zones) can be seen.

Lastly, I apologize for being wry.  Well, OK, maybe I don't. TGIF


Anthony