
08-29-2007
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Telstar 28
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Join Date: Mar 2006
Location: New England
Posts: 43,315
Rep Power: 10
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Wayne-
Most people use binocs that are 7x50, since they're a good compromise between magnification and low-light gathering ability.
The first number is magnification... and the higher the number, the more "jumpy" the binocs will be.
The second is the objective diameter... and if you divide it by the magnification, you'll get the exit pupil diameter. In this case it is about 7mm... that means at night your pupils can be 7mm in effective diameter... if the binocs were 10x50's, then the exit pupil would be only 5mm and effectively half the light your eyes can gather. The larger the exit pupil, the brighter the binocs will appear at night.
Stabilized binocs rely on electronics to do the stabilization and often have higher magnifications, which makes it harder to find what you're looking for, since the angle of view in narrower, and generally do not work as well in low light, since the exit apertures are smaller... allowing less light through. Also, if the electronics fail, they're pretty useless aboard a boat, since the higher magnification makes it pretty much impossible to use them without the stabilization.
You really do want a waterproof set, since the expansion and contraction of air in a non-waterproof set will often lead to condensation inside the body and that leads to mold/mildew growing on the lenses. Not to mention, if they do end up on the cockpit floor, and get wet... they're much more likely to survive being waterproof and nitrogen filled.
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Sailingdog
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Telstar 28
New England
You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
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Last edited by sailingdog; 08-29-2007 at 11:36 AM.
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