stereoscopic range finder

A stereoscopic range finder is an instrument used to measure distances. It operates on a principle similar to coincidence range finders but uses two eyepieces instead of one, allowing for more effective sighting of moving objects. This type of range finder was widely employed for land-gunnery during World War II.1

The effectiveness of stereoscopic range finders is rooted in the principles of binocular vision, where the brain processes slightly different images from each eye to perceive depth. This ability to perceive depth from dissimilar images is crucial for accurately determining distances, especially to moving targets. While radar and laser range finders have largely replaced optical versions in many military and surveying applications, the stereoscopic principle remains a fundamental concept in understanding depth perception.21