What does the first number in a binocular mean, such as the 8 in 8×40?
A2. The first number – the ‘8′ in an 8 x 40 or ‘10′ in a 10 x 42 is the magnification. Magnification simply means how many times the image is enlarged over its normal size when you look through the binocular. Stated another way, magnification is how many times closer the subject appears to be in a binocular than it actually is. When looking at an object 100 yards away through a 10 x 40mm binocular, the subject will appear to be ten yards away. Always remember that a 10×50, 10×40, and 10 x 42 are all 10x binoculars and each magnify an identical 10x. Note that in ‘zoom binoculars’, the first two numbers out of three, represent the magnification range. In a 7-15×40, for instance, you can change the magnification from 7x up to 15x by ‘zooming’ in. Be careful with magnification because more is not always better. The affect of higher magnification means that both the image brightness and field of view (the amount of territory seen through the binocular) will lessen. And also equally as impor
