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Re: [ATM] getting the foucault test right
David,
>so that I can show you guys what it looks like so that I
>can get your advice on what to do next.
There is excellent program from James Burrows
simulating shadows from Foucault testing. I recommend you
to make yourself familiar with this program in order to
see what to expect.
>The problem with all of these is that the Foucault test is
>so sensitive that I barely move and the image is off.
>And I have the camera mounted on a tripod,
>but that doesn't help either.
At my mirror grinding course mentor took pictures of
Foucaultgrams with camera holding it in his hand.
His was single lens camera 35mm film. No problems.
>I have the foucault tester and the 20", 1" thick mirror,
> uncoated, and I think that it is hyperbolic
If you have Foucault tester than you should know if
the mirror is or is not hyperbolic. Just put measurements
into one of available data reduction programs and
you will get the best fit conic constant for the mirror.
If you do not know how to use the tester, please read first
"Understanding Foucault A Primer for Beginners" By David Anthony Harbour
>What does anyone think about the couder mask that I made, here it is:
I think you are missing a zone or two or even three for 20" mirror.
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