A Telecentric lens is a kind of lens that the chief rays are parallel to the optical axis. There are three kinds of telecentric lens, that is the object-space telecentric lens, image-space telecentric lens, and the bi-telecentric lens. Telecentric lens is always the core business of� Canrill Lens. After continuous research and development for 11 years, Canrill has successfully developed 1700+ kinds of lenses, and the number is still increasing, to meet the diverse and growing applications at the best telecentric lens price. Difference Between Object Space Telecentric Lens And Bi Telecentric Lens Telecentric lenses have two types of telecentricity: telecentric objective space and image space telecentricity (referring to the entrance and exit pupil positions, respectively). Therefore, telecentric lenses are divided into: object space telecentric lens, image space telecentric lens, and bi telecentric lens. Object Space Telecentric Lens In general, a machine vision telecentric lens refers to an object space telecentric lens. If the entrance pupil of the lens is located at an infinite position in the image side (all objects behind the objective lens), it can be called an object space telecentric lens.� The chief ray originated from optical axis is parallel with optical axis in object side ( or to say have very small angle �¸ which is called telecentricity in telecentric lens specs), while in image side is not parallel. china bi telecentric lens with entrance pupil projected to infinity on the image side In the optical design, object space telecentricity is achieved by placing the system's iris diaphragm at the intersection of the front-end groups. Since the entrance pupil is at infinity, the field of view is constant and has no field angle. Since the chief ray (which defines the system's field of view) passes through the optical axis at the aperture stop, when the pupil is at infinity, the ray is parallel to the optical axis and the field of view is zero. By contrast, any entrance pupil within a finite distance of the lens results in a non-parallel fiber.