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    Re: Navigator's Vision,Day or Night.
    From: Greg Rudzinski
    Date: 2009 Oct 5, 14:53 -0700

    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
    On Oct 5, 2:30�pm, QMCM  wrote:
    > 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 -
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