When shopping for a pair of binoculars it's important to give equal value to both numbers on the binoculars. It's nice to have a pair with a high magnification, but if the number on the right is too small, your subject may be dim and your depth of field shallow.
Number on Left
The number on the left represents magnification. For a pair of 7x30 binoculars, the magnification is 7.
Magnification will tell you how many times that an image has been magnified. The larger the magnification, the more powerful the binoculars.
Number on Right
The number on the right indicates the size of the objective lens in millimeters. A pair of binoculars labeled 7x30 has a lens 30 mm wide.
The objective lens is the lens that points at the subject. The bigger the objective lens the more light that enters the lens, creating a brighter image and a wider depth of field.
The x between the numbers represents "times." A pair of binoculars that says 7x30 has a magnification of 7 times an objective lens of 30 mm. The larger both numbers, the more powerful the binoculars.
Article Written By Shiromi Nassreen
Shiromi Nassreen has been writing professionally since 2005. She specializes in travel and outdoor topics, and her articles have appeared in various print and online publications, including "DISfunkshion Magazine" and Matador Travel. Nassreen holds a Bachelor of Arts in theatre studies from Rose Bruford College of Speech & Drama.