Re: ATM Astigmatic zone

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

My suspicions are that the mirror mount is producing some astigmatism but
you say that just the mirror is producing the error.  If the glass is plate,
you could have some residual stress in the glass which would be sad at this
point.
About the best test would be to rework your Foucault tester so that you can
take the KE and light and rotate it by 90 deg. so you can test at different
angles.  If desired, make a simple slitless head with a tube with a LED
inside and a blade and attach to the tester.  K&S makes some telescoping
tubing that you can use to makeup a rotating section.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
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