From: Guy Brandenburg 
To: Stan Truitt 
CC:  atm{at}shore.net
Reply-To: Guy Brandenburg 


Thanks to all who responded for my requests for suggestions on the testing
of aluminized flats. If I may summarize the responses, I think I read the
following:
(1) The reflection from the aluminized surface overwhelms the diffraction
effect, so I should partially aluminize one side of my reference flat.
(2) My monochromatic light source is not pure enough - get a better one.
(3) My flat and my mirror are not clean enough, so they are not in good
enough contact to show the rings. They REALLY have to be REALLY, REALLY
clean and dry (5 minutes +) for there to be good enough contact. (4) First
try it out on a piece of clean plate glass to see if I can see anything at
all.
(5) Try interposing a piece of nylon stocking or bug screen. (6) I should
be seeing it with no problem even with ordinary, unfiltered fluorescent
lights.

I will try #4, 5, and 3 tonight, and will share the results.
--
Guy Brandenburg
Washington DC, USA
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html

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