What is the magnification of a pair of binoculars?

Magnification is the degree to which the object being viewed is enlarged, and is designated on binoculars as the number preceding the "x." For example, when using an 8x42 binocular, 8x represents the binocular's power. An 8x magnifies an image to eight times the size it would be when viewed by the normal, unaided human eye. Similarly, a 15x70 binocular magnifies an image 15 times, and so on.

The level of power also affects the brightness of an image: the lower the power, the brighter the image. In general, increasing power will reduce both field of view and eye relief.
magnification marking
Magnification is marked on
many pairs of binoculars.  

Magnification Comparisons:
unadied eye

Updated 10/21/13