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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Bris does not work
From: Alexandre Eremenko
Date: 2012 Jul 26, 14:57 -0400
From: Alexandre Eremenko
Date: 2012 Jul 26, 14:57 -0400
Greg, Aha, if there are three reflecting surfaces, then mathematically it is the same as the standard Bris. > The 2,3,3 grouping is by angle. Reflections 1,3,4 of 8 are bright. Same as it used to be with my one. Still I don't understand these numbers (bright, dim)=(3,5). We have 3 surfaces, say 1,2,3, counting from Sun to the eye. Then the three bright images must occur when two reflections happen, that is (2,1), (3,1) and (3,2). Now the dim ones must be due to 4 reflections for which we have these possibilities: (2,1,2,1), (2,1,3,1), (2,1,3,2), (3,1,2,1), (3,1,3,1), (3,1,3,2), (3,2,3,1), (3,2,3,2). So there should be 3 bright and 8 dim images. Why then we have only 5 dim? Which 5 and what is special for these 5? Alex. > My camera Bris actually has three glass reflectors. > The camera filter itself counts as a reflective glass plus the two > microscope slides that are added.
