Re: ATM Foucault test accuracy

["Frank Ward" <thewards@mindspring.com>]

Steve,  You wrote >I like to judge the shadows when they just begin to
darken in the Couder
 windows<

Interesting post, I use the blink method to judge the balance
between two zones but (several mirrors I've made startested
as overcorrected. You might have pointed me toward >my<
systematic error. Anyone else out there want to comment on
this?

I remember a discussion awhile back when Nils Olaf and Jim
Burrows were calling the center of the zone the most accurate
point to hit. That's logical, but in practice the only way to do that
accurately would be with a pinstick and I've switched to the
mask because the pinstick left too much for me to "interpret" (read
that "fudge") when I was anxious or tired.

  Question proposed: Mirrors tested with the shadow "just appearing" might
startest undercorrected and mirrors tested with the shadow filling
the zone and blinking equally with each other might startest as
overcorrected.

Frank Ward
Atlanta, GA
 > Steve Lindberg, Olympia, WA
 (original message deleted to help  keep Clive's finger where it is)