NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Digital Camera Sextant Hybrid
From: Frank Reed
Date: 2008 Dec 5, 11:54 -0800
From: Frank Reed
Date: 2008 Dec 5, 11:54 -0800
Greg, a couple of weeks ago, you wrote: "The Brissextant can be attached to a digital camera lens to create a hybrid celestial navigation instrument. I believe this would be the next sensible evolution of digital camera CN." It's an interesting idea. Bear in mind that you still have to "swing the arc" with a fixed-angle sextant (like the Bris) and you also have to align it carefully to ensure that the line of sight is collimated relative to the mirrors. "Does anyone know where I can get a Brissextant?" As others already mentioned, they're easy to make. You may also want to experiment with an ordinary fixed-angle sextant. To see what I mean, look at a standard sextant set to, say, 45 degrees. Now fade out all of the components except the index mirror and the horizon glass. They are the essential components that make the sextant work as it does. Afix those to a simple flat board replacing the sextant frame. The mirrors can be permanently glued to the board. They do not need to be adjustable. A fixed-angle sextant like this is easy to make. You could build a dozen of them, one for every ten degrees of altitude. And they can be quite compact, an inch or two on a side, like the original Bris sextant. The big advantage of the Bris design is that you get several fixed angles in one device. The disadvantage of the original Bris design is that it works primarily with the Sun, the Moon is you're lucky. A simple fixed-angle device can be extended in all the usual ways that sextants have evolved. You could hold one in front of a small spotting scope if you want higher magnification. You could add shades for viewing the Sun as well as the stars. You could even add some sort of adjustable arm and a scale to... wait, wait... we're back where we started. :-) -FER --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---