What is a telecentric lens?

A telecentric lens is a video imaging lens that optically corrects for perspective errors due to parallax. Telecentric lenses yield constant magnification over a range of working distances, virtually eliminating viewing angle error. Objects in the field of view of a telecentric lens maintain their perceived size no matter where they are located. These lenses are widely used in machine vision systems that require accurate measurements of three-dimensional objects with slight height variations. By eliminating the perspective errors and magnification errors inherent in conventional lenses, telecentric lenses yield dimensionally accurate images that are easily interpreted by software. For a more detailed look at telecentric lenses, view The Advantages of Telecentricity.