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: Greg Rudzinski
Date: 2009 Oct 5, 14:53 -0700
From: Greg Rudzinski
Date: 2009 Oct 5, 14:53 -0700
Byron, Can you describe what it was like making an observation from a Polaris Sub? Was it done on the Conning tower or could it be done through the periscope? Greg On Oct 5, 2:30�pm, QMCMwrote: > No I am still in to Navigation, because of my Navy past. Using only > Navy sextants and they were not the best. Even on the Polaris Sub's > with all the good electronic gear, we had only one standard Navy > Sextant. > Byron. > > On Oct 5, 2:39�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.- Hide quoted text - > > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---