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    Re: Polariser (photo) filter as a sextant shade - my experience.
    From: Ed Popko
    Date: 2019 Apr 27, 09:31 -0700

    Tony,

    I have a C&P Horizon model sextant and it has a factory installed rotating polarizing horizon filter.  I don't use it much but on open water or from shore, it makes quite a difference. When I don't use it in these cases, my observed height is always more than it should be which results in 'towards' intercept. Why? Because the reflection does not start at the horizon but a little below it.

    The Moon's reflection is the same, the actual horizon is always above the first part of the reflection. I only have a few moon-over-water shots but this sees to be the way the horizon and the reflection's beginning work.

    Ed

       
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