Telecentric lenses are special lenses which can be used in machine vision systems and imaging systems to maximize performance and provide highly accurate, repeatable measurements. Shanghai Optics manufactures both object-space and image-space telecentric lenses, and we are able to provide stock parts, pre-engineered specifications, and fully custom lenses.
Our pre-engineered lenses give our customers the option to choose from a variety of preliminary designs based on what suits their application best. Just tell us your application requirements (dimensions, wavelength range, field of view, etc.) and our team of expert engineers will optimize our preliminary designs to meet your exact needs. This will save you the hassle of fully designing a product from scratch and can help reduce or eliminate design fees!
Telecentric lenses are designed to have the entrance and/or exit pupil at infinity. For telecentric lenses, all the chief rays are parallel to the optical axis in either image space or object space, or both. Telecentric lenses are used in imaging systems or projection systems to increase the measurement accuracy as compared to conventional lenses.
For an object space telecentric lens the entrance pupil is at infinity. All the chief rays are parallel to the optical axis in the object space. When an object-space telecentric lens is used in a machine vision system the image magnification will be independent of the position within the field of view as well as of independent of the object’s distance.
An image space telecentric lens features the exit pupil at infinity. Here the chief ray is parallel to the optical axis in the image space. Such lenses can be used in dimensioning systems for making the measurement accuracy be independent of the image sensor’s distance ( within the depth of focus) in the field of view.
For a double telecentric or bi-telecentric lens, both pupils are at infinity. In this type of lens the chief rays are parallel to the optical axis in both the object space and image space. With bi-telecentric lenses, the magnification in both image and object space is independent of distance or the position in the field of view. Such lenses can be used in a wide range of applications.
Ordinary, conventional lenses have angular fields of view. As the distance between one of these conventional lenses and the object increase, the magnification will decrease. This angular field of view also causes perspective error (parallax).
Telecentric lenses feature a constant field of view that is non angular: the field of view does not depend on the distance. This means magnification doesn’t change based on depth. It turns out this is extremely helpful for machine vision applications: often, the positioning of parts varies between objects, and using a telecentric lens allows us to get consistent imaging even when a conventional lens would give us calibration errors.
While telecentric lenses don’t have a larger depth of field, inherently, any blurring that happens is symmetrical over both sides of the focal point. This means that features of interest (corners, say) will maintain their center of mass location and can be measured accurately even if they are not completely in focus.
Telecentric lenses also have lower distortion values than your conventional lens. This makes the distortion-eliminating calibrations we often perform as a matter of course unnecessary, leading to a much lower CPU load in measurement software.
Shanghai Optics can quickly and cost effectively provide customers with high performance telecentric lenses for use in a variety of applications including machine vision, inspection, metrology, image sensor tests, and projection systems. We are proud to offer the best price to performance ratio you’ll find anywhere in the industry, and our rugged housing means that our telecentric lenses will be well protected and perform consistently in spite of harsh environments. While our in-stock lenses feature a standard lens mount, we can provide custom lens mounts and coatings on request.
Unlike other optical supply warehouses which simply stock and sell lenses manufactured elsewhere, all our stock is proudly made in-house in our own factories. This allows us to ensure unmatched quality. Each lens is carefully tested and subject to careful quality control, and we provide a detailed test report for each lens.