NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Norm Goldblatt
Date: 2013 Sep 30, 15:48 -0700
Eclipse glasses on paper frames are available for about $2. You MUST assure by specification of filter that it blocks out near IR as well as visible. Eclipse glasses satisfy this important criterion. The film that is used for viewing eclipses is perfect, but it punctures easily. However, one little pinhole in the filter isn't going to blind you.
And DEFINITELY put the filter in front of the objective lens. If you put it anywhere else, it not only can cook your crosshairs, the power density could be great enough to punch through the filter itself.
Norm
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