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    Re: Hello and a question about polarizer sun filters
    From: Wayne Hilliard
    Date: 2016 Dec 6, 12:34 -0800

    According to general astronomical knowledge there are 3 options for safe viewing of the sun with optics. Projection onto a screen, metallized glass filter or metallized mylar film in a frame. For naked eye viewing of the sun with #14 welders glass.  The po!arizer shades on my mark 2 sextant makes more sense to me then the colored plastic shades on the Davis plastic sextant I have. I have judged the thickness on vacuum deposited aluminum onto telescope optics by holding up and viewing the sun through it, If you see a dim blueish disk then you have about 100 nanometers of deposit. No idea on the testing of shades.

    Wayne

       
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