| NATIONAL PARKS QUICKLINKS |
Backpacker Magazine – March 2008
Get Clarity
Learning a bit of jargon will help you find your ideal binoculars.
Magnification
10x means the lenses magnify 10 times more than the naked eye, so an elk at 1,000 yards appears only 100 yards away.
Lens size
The larger the diameter of the front lens (measured in mm), the more light it collects. That results in a sharper and brighter image, in addition to a higher relative brightness level.
Eye relief
The distance (in mm) your eyes must be from the eyepiece to see the entire field of view. Smaller eye relief distances can strain your vision. Glasses-wearers should seek out an eye relief of 11mm or more.
Field of view
The width (in feet) of the area observed at 1,000 yards. The smaller the field of view, the more powerful the magnification, and the smaller the eye relief.
Waterproof
To make top-end binoculars waterproof and fogproof, optical spaces are filled with nitrogen gas and sealed with rubber O-rings.
Relative brightness
This index represents the quantity of light gathered by a binocular's lenses. Levels from 4 to 16 are best for daylight; 16 to 25 are optimal for dawn to dusk; anything above 25 is suitable for all light conditions.

Editors' Choice 2013
Boost Your Apps
Carry the Best Maps
FREE Rocky Mountain Trip Planner
Survival Skills 101 • Eat Better
READERS COMMENTS
Have a pair of Leica 8x42's, and a pair of REI 8x42's. The 6x disparity in price is not reflected in the optics: REI's waterproof 8x42's are clear, bright and rugged. Not as clear and bright as the Leicas, and don't have Leica's "you break, we replace" lifetime warranty, but pretty darn good glass for the money.
Eye relief doesn't measure strain on your eyes, nor does it translate into field of view.
ADD A COMMENT