What is a telecentric lens?
Telecentricity is a special case where the principal optical rays are parallel to the lens's optical axis. In an object-side telecentric, the lens on the object side (as opposed to the camera side) principal rays are parallel to the optical axis, this eliminates perspective errors . An object is always displayed the same size at different working distances, i.e. the magnification does not change with varying working distances. Telecentric lenses are generally used where distance and location of the test object can affect the measurement accuracy and are ideal for precision measurement applications. Due to the parallel beam path telecentric lenses can be used to image critical and awkward optical surfaces and material properties for example high gloss, optically active materials, variable edge shapes, glass etc.