Re: [ATM] ATM Digest, Vol 30, Issue 21

[Jim Burrows <burrjaw@earthlink.net>]

At 2006-06-16 16:17 -0500, Stephen Koehler wrote:

> > In Germany we had a mirror testing project. 16 persons were testing one
> > astigmatic mirror
> > and the main problem was the support of that astigmatic mirror.
>
>This seems to directly pertain to my recent post to the interferometry
>group, where I describe a new (to me) algorithm for separating mirror
>from test stand aberrations from Zernike coefficients from the mirror
>at various angles of rotation.

The simplest theoretical way to measure the on-the-glass astigmatism, but 
not very easy in practice, is to "mount" the mirror without test-stand 
astigmatism, i.e., do the test with the mirror lying flat on the 
floor.  Not recommended for a long-focus mirror unless you're testing in a 
cathedral.

         -- Jim Burrows
         -- mailto://burrjaw@earthlink.net
         -- http://home.earthlink.net/~burrjaw
         -- Seattle N47.4723 W122.3662 (WGS84) 

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