Binoculars

Optical performance relies on the successful balance of a number of factors.  When each factor is optimized, the result is an instrument with outstanding visual performance.  Shark Tested Products carries the finest binoculars from Bushnell and Bausch & Lomb.  Click Here to browse our online catalog of Binoculars.

Binocular Terminology  from Bushnell

Magnification - Magnification is simply the degree to which the object is enlarged.  With a 7 x 35 binocular, for example, the object appears to be seven times closer than without the aid of a binocular.  The number immediately following the "x" is the diameter in millimeters of the objective (front) lens.  A 10 x 50 binocular, therefore, has 10 times magnification with a 50mm objective lens.

Exit Pupil - The exit pupil refers to the size of the shaft of light transmitted to the eye.  The more light, the better the contrast.  You can actually see the exit pupil by holding the eyepiece of the binocular approximately 12 inches from your eye.  It is the bright circle of light in the center of the eyepiece.  Exit pupil is expressed in millimeters and is normally derived by dividing the power into the objective lens diameter.  A 7 x 35 binocular has an exit pupil of 5mm (35 divided by 7).  A 15 power telescope with a 60mm objective lens diameter has an exit pupil of 4mm.

Field of View - The field of view is the width, measured in degrees or feet, of the viewing area you would see at 1000 yards.