Re: ATM New mask for Foucault

["Bill T." <twentiethwave@hotmail.com>]

>TV screen. Then two photocells with a comparator were placed on the TV 
>screen
>to measure when the brightness of each pair of zones matched.

Don't have that issue, but there is an extremely good article titled 
"Digital Knife-Edge Test Reduction" by Harold R. Suiter in ATM Journal #13.

Also, Michael Peck has an outstanding web page on the subject:

http://home.netcom.com/~mpeck1/astro/autof.htm


Bill Tondreau
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