Re: [ATM] marking the center of a circle

["Bob May" <rmay@nethere.com>]

The only question here that I have is how far off are we talking
about???  There's a big difference between a tenth of an inch and
an inch for being off-center.  A tenth of an inch on a twelve
inch mirror is hardly anything at F6 or so while an inch will be.
What happens to the testing via the "standard" Foucault testing?
Also, how much variance do you get as the mirror rotates with a
perfect parabola behind the mask?
The only way that I can see to get the center way off is in
stressed mirror parabola figuring.
Bob May
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