Range Finder

A range finder is a device that allows its operator to measure a distance via optical means, rather than using tools like tape measures or trundle wheels, or predetermined distances between landmarks. There are various ways to find ranges in this manner:
 * Devices such as macrometers allow the user to compute the range by aligning two images and measuring its offset.
 * Stadiametric range finders measure the image height of a known object. These may appear in scopes, allowing a shooter to estimate range given a soldier's average height of 1.7 meters.
 * Telephoto lenses can be used for ranging by precisely focusing on the target and reading the lens markings.
 * A laser range finder emits coded pulses of light and measures the offset from the reflected beam.

Battlefield 2142
Many weapons (infantry and vehicle) in Battlefield 2142 had a range finder integrated into its sight.

The PK-74 AR-Rocket has an adjustable range finder that allows its user to set a point of detonation for fired rockets.

Battlefield 4
The Range Finder attachment is introduced in Battlefield 4. It is usually seen mounted on the left accessory rail, visible when hipfiring. The range finder displays the range to the spot targeted by the weapon's crosshairs, and the current zeroing of the attached scope. When aiming down sight, the range and zeroing also appear imprinted in the scope view.