[ATM] testing an f/2.6 mirror?
burrjaw at earthlink.net
Mon Dec 17 09:37:07 JST 2007
At 2007-12-16 05:33 -0800, Guy Brandenburg wrote:
>Somebody wants me to test test an f/2.6 mirror, (8 inch diameter)?
>Sounds to me like something one would need a wire test to do, and
>I've never done that before. Any thoughts?
The lateral wire test (LWT) is much better than Foucault at that f/,
and better than Ronchi because you get measurements rather than
guesses. Essentially you mount a "pinstick" on the mirror rather
than a mask, and run the source and wire beyond the mirror's
ROC. Sixtests has a few words about reducing the test data:
(Win32, 2007-03-17, 372 k)
Let's see, Diffract has some simulations of what you see in a wire test:
(Win32, 2004-04-12, 375 k)
It's cute - the wire shadow has a bright line in the center - helps measuring.
Some of the other test routines (FigureXP?) may have something, too.
-- Jim Burrows
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-- Seattle N47.4723 W122.3662 (WGS84)
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