What is an optical rangefinder and how does it work?

An optical rangefinder is a device used to measure the distance to a target by utilizing the principles of triangulation. It typically consists of two lenses that capture images of the target from slightly different angles. By comparing the apparent displacement of the target against a known baseline distance, the device can calculate the distance based on geometry. The user aligns the images, and the rangefinder provides a distance reading, often using a reticle or other visual aids for accuracy.