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Re: First Time

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Posted by Walter Hamler on April 17, 2002 12:53:29 UTC

You need to get your eye as close as possible to the knife edge. Make sure the mirror is fully illuminated. Are you using a slit or pinhole? By moving the tester back and forth while watching the light in the mirror you should be able to find the spot where the mirror is fully illuminated. Then the knife edge shadow should be easy to see as you push it into the beam. If you have a good sphere, and are at the exact roc, the miror will darken very quickly and seemingly from no particular direction.

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