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    DIY "Bris mini-sextant": what angles to aim for (and other suggestions)?
    From: Tony Oz
    Date: 2016 Sep 21, 02:24 -0700

    I'm experimenting with few bits of glass to build a DIY "Bris".

    This article describes a tool with a set of reflections at 13°, 22°, 26°, 35°, 44°, 48°, 57° and 70°. Is this set optimal for real-life observations? If not - what agnle values should I aim for in my design?

    I hope to use it (or - most probably - a pair of "Bris"s) somewhere between equator and 60°.

    The other question: what size of the device is most comfortable?

    Right now my pieces of glass are 25mm·15mm - similar to author's article. I tried them on a sunny day - it was painfull to use (despite the 9 DIN welding filter was used) because 15mm-narrow "bris" does not cover the eyeball enough. The bright light from the right and left part of the sky still blinds me. When I did my initial tests with the uncut filter (110mm·150mm) there was no such problem. I'd like to avoid using any rubber eyecups...

    Please share your experience.

    Regards,

    Tony

       
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