Re: ATM ronchi patterns vs foucault

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

When you compare the results as shown by the TEX graphic of the mirror shape
and the Ronchi Test, you will see the similarity of the shape.  Remember
that you are looking at the ROC of the various zones with the Foucault test
and looking at the curvature changes with the Ronchi and you probably have a
hole in the middle of the mirror which is not as bad as you would think if
it's small as you will be covering it with the secondary's shadow.  I also
prefer to use a zone set that is midway between the "standard" of TEX and an
equidistant zone set to minimize the problems of finding the center of the
mirror's ROC.  Try a 5 zone equidistant distance mask and see the center
hole better.
Bob May
My new web space address is http://webu.wigloo.com/bobmay/ or
http://nav.to/bobmay
and my new email address is bobmay@nethere.com
Bob May