NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Navigator's Vision,Day or Night.
From: Tom Sult
Date: 2009 Oct 05, 19:54 -0500
From: Tom Sult
Date: 2009 Oct 05, 19:54 -0500
I have not seen night vision optic that can focus that close... perhaps the military types have... I have a pair of goggles I use in my plane at night. Thomas A. Sult, MD IntegraCare Clinic www.icareclinics.com tsult@mac.com On Oct 5, 2009, at 1:39 PM, Greg Rudzinski wrote: > > Byron, > > Have you ever used electronic night vision optics on a sextant? If so > what are the pros and cons? > > Greg > > On Oct 5, 9:34 am,wrote: >> Navigator's vision at day and night. >> The way you use your eyes at night is different from the way you >> use them during the day. With normal day vision, you train your >> eyes to look directly at the target. If you catch something out of >> the corner of your eye, you automatically move your eyes to center >> on the target. Once you have done so, you can see the target >> clearly in color, and detail. In the dark, however, instead of >> directing your vision at the area you desire to see, you must learn >> to use off-center vision for a very dim light or star. The first >> step in training yourself in night vision is finding a location >> free of normal white city lights, Perhaps your backyard or better >> at sea. Wait until your eyes have adapted to the dark; this can >> take about 15 to 20 minutes. At this point the sky is black, some >> stars are bright, or some dim and you are aware of your >> surroundings. Your eyes are accustomed to the dark. If you need a >> light to read/write or see a star finder (NAVLIST 9471) use a red >> dim light only. Look at the sky and find a bright star. Now slowly >> move your eyes until you see, or think you see, the dimmest star >> out of the corner of your eye. Look directly at the star. If it is >> a very dim star it will "disappear" when you look at it and won't >> reappear until you move your eyes and "look" at it using the off- >> center technique. It may well be fuzzy and lack color. But you do >> see it. What is happening here is that you are seeing it with your >> peripheral vision. Practice this off-center technique until you are >> comfortable picking up even the dimmest star. Binoculars can help >> make some of the dimmer stars very bright. But other stars will >> disappear when you look directly at them, even with binoculars. At >> sea at night, relax and move your eyes slowly just a few degrees >> around the sky or the horizon. If you think you see a light, use >> the off-center vision technique to isolate your target. If the >> light is very faint and disappears, use a slow, off-center eye >> motion to pick it up again. Then use your binoculars to pick up any >> color details. Practice this off-center procedure until you are >> proficient in seeing things at night. When you are in the darkness, >> only a trained eye can produce the correct information quickly. In >> the day time when you want that good horizon for a star or planet >> before dark thickens the horizon try the "Vertical Sextant" NAVLIST >> of Sept 28. > > --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---