Re: [ATM] Testing small mirrors

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

I don't know but 2" mirrors are not that small if you build the
tester small enough and use a camera for the image viewer.
The secret here is to get the light source and the returned image
close together to reduce the error in the vertical directon to
something minimal.  I'm presently contemplating a tester that can
test an even smaller mirror for a Gregorian (about an inch in
diameter) and will be basically building the whole thing on the
end of the lens (probably use a 1/4" or so lens for the camera
and glue the KE to the lens)
The difficult thing here is the short FL of the mirror as this
sets a lot of the geometry of where the problems will be
occuring.  Longer focal length mirrors are a lot easier to test.

Bob May
bobmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
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