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    Re: Lunar contrast
    From: Hewitt Schlereth
    Date: 2016 Sep 12, 07:35 -0700
    Got it. Thanks, Geoffrey.

    Hewitt

    On Sep 11, 2016, at 11:13 PM, Geoffrey Kolbe <NoReply_GeoffreyKolbe@fer3.com> wrote:



    On 11 September 2016 at 20:18, Hewitt Schlereth <NoReply_Schlereth@fer3.com> wrote:
    Would polarized sunglasses work?

    Hewitt

    ​You can certainly see the effect using polarized sunglasses. But you need to rotate the sunglasses (or your head)  as you look up to the sky to align the polarization axis of your glasses correctly. If aligned correctly, you will see a dark band in the sky from horizon to horizon through an arc at 90 degrees to the sun. I suspect it will be inconvenient to align you glasses and your sextant at the same time to take a lunar. Best to have a polarizing element on the sextant itself. A polarizer on the sextant only needs to be aligned once. Thereafter, it will be correctly aligned for all lunars.

    Geoffrey​

       
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