[ATM] Re: ATM chinese puzzler

["Donald \"Don\" Ware" <mimas@charter.net>]

About a year ago I needed a mirror with a short RoC to demonstrate Foucault
testing.  I ordered a 6" f/5 1/4 wave PV parabolic mirror from a company in
Tennessee.   It was obviously of Far East origin judging by the paper it was
wrapped in.  The figure was the worst commercial mirror I've ever seen.

Essentially an oblate spheroid with a deep hole in the center.  Strehl of
0.05.
Company allowed me to exchange it, but the second one was just as bad.
Useless for demonstrating Foucault as there was no obvious pattern to the
zone
intensities.

Perhaps the mirrors signaled to go in one direction went to M**e, C****n,
etc. and
the ones in the other direction to Tennessee.  That way the operators
wouldn't
need to know what the tester's decision was.

Don Ware
Hollis, NH
http://webpages.charter.net/dware1/



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