How to Choose
Waterproof/fogproof optics can endure even the wettest conditions.
to keep in mind when making a selection:
Under what light conditions are you usually outdoors?
In bright daylight or during the most subdued shadows and haze of early morning and late afternoon? Some optics pull in more light to brighten your subject, while others are suited only for full daylight viewing.
A product's specifications can provide a pretty good indication of light gathering ability. Binocular specs, for instance, are given in two numbers divided by an "x": 7 x 35, for instance, or 10 x 50.
The first number is the magnifying power, the second is the diameter (in millimeters) of the objective (front) lens.
The diameter of this front lens is important in determining light gathering ability, since the wider the lens, the more light it will allow to enter.
The brightness of the image is determined by the size of the exit pupil, which is the concentrated light coming out of the eyepiece.
The larger the exit pupil, the greater the brightness of the image.
There are many more factors to consider, even in terms of light magnification. For more information, continue to Part 2