Rangefinder

Rangefinder cameras are the dual-image devices those allow two super imposed images appear in a line to get the focusing in a very efficient way to measure the distance from the target. The gadget usually comes with a split-image rangefinder in order that users can take snaps with a sharp focus. There are laser range finders which work on the same concept. When you press the button, the laser beam will be emitted by the rangefinder. The high-speed clock will determine the travelling distance and the return of the laser beam.