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Old 03-12-2005, 05:36 PM
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Starkler (Geoff)
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Join Date: Sep 2004
Location: Melbourne
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Dave what we call the boundary layer is a layer of warmed air sitting on the face of a mirror which is warmer than ambient. This acts as a wavering lens and distorts the view.

There are two ways to attack this problem:
1: flush the boundary layer air out of the optical path.
2: make the mirror temp the same as ambient in the tube so there is no boundary layer.
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