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    Re: Tinkering with Davis sextant scope
    From: Bill Morris
    Date: 2011 Apr 9, 13:04 -0700

    This is a very interesting conversion.

    The bright, erect field of a prismatic monocular is always a revelation and, as Rolf writes "using a traditional mirror became easier". This is because the optics of the supplied Galilean telescope mean that each half of the objective "sees" only its own half of the field, while that of the Keplerian optics of the monocular "sees" the whole field, and the overlap of index and horizon images is much more pronounced. Thus, with the former, if you cover half the objective, you lose half of the field of the view, while with the Keplerian, the view stays the same but becomes half as bright.

    Would optical experts care to comment on the rather small aperture of 12 mm?
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