A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Bris "Sextant" questions.
From: Greg Rudzinski
Date: 2015 Jun 10, 15:01 -0700
The Bris works just like a sextant so the lower limb is actually the lower limb. You can use three panes or four. Four panes has quite a few Suns making for busy observing. Or make two Bris with triple panes of different fixed angle sets. For the advanced Bris craftsman try various camera filters and spacers with panes glued to the filters. This will combine digital camera pixel counting with fixed Bris Sun angles for anytime Sun camera observation pics.
From: Marty Lyons
Date: 2015 Jun 10, 14:33 -0700
I have read what is in the archives. I want to make a Bris, using two clear 2" x 4 1/4" lenses from a welding helmet and a #5 shaded lens. #5 seems to be a good compromise between seeing the horizon and protecting your eye. I realize that a #5 shade is not dark enough for direct viewing of the sun.
1. Is it better to have as many reflections as practical to allow sights at many different times of day, rather than just two reflections?
2. Concerning the angles, is it better to have the reflections widely spaced so they move down to the horizon quicker therefore allowing a more accurate timing of the lower limb tangency?
3. Since these are reflections, is what appears to be the lower limbs actually that, or an upper limb in upside down?
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