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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant Telescopes
From: Rodney Myrvaagnes
Date: 2004 Mar 28, 22:23 -0500
From: Rodney Myrvaagnes
Date: 2004 Mar 28, 22:23 -0500
On Sun, 28 Mar 2004 07:42:50 -0500, Joel Jacobs wrote: > >A 4 x 40 is considered a STAR Scope because it transmits more light through >the optics than higher powered scopes. Its wider field of vision is an >advantage in low light conditions. > It isn't so much the field of view as the f/stop (in camera speak) that makes the 40 mm objective better than a 30. The 7X50, if the optics are good, makes a great twilight glass for lloking into an anchorage when you can't se in the shadows with the naked eye. The same quality would help gather light from a star. I have a question. has anyone adapted an image-stabilized glass to a sextant? A few weeks birding with a Canon 6X30 IS binocular suggests it (one barrel of it) would be usable on a small craft, which an unstabilized 6X30 really is not in any wave action. I am sure you can't just saw it in two, because the motion sensor is certainly shared. Given the small market for sextants, I suppose it is unlikely any of the optics companies will make a sextant scope in the future with this feature. Rodney Myrvaagnes NYC J36 Gjo/a "Accordions don't play 'Lady of Spain.' People play 'Lady of Spain."
