TD telecentric lenses
Lensation has released TD telecentric lenses. Designed for use with sensors featuring a 4, 12, or 16 Megapixel resolution, they are available in three versions with working distances of 256, 400 and 470mm and magnification factors of 0.38, 0.24 und 0.1. They provide reliably measured data in inspection and measuring tasks with varying distances between the camera and the measured object. The lenses are well-suited for tasks such as offline shape measurement of large extruded plastic and metal parts.
Conventional lenses act similar to the human eye: approaching objects seem to grow larger. With telecentric lenses however, the object size does not change, allowing them to detect the size of an object even when its distance is not known.
Object-space telecentric lenses are used to detect objects without any perspective distortion. This requires a front lens that is at least as big as the object to be measured. The magnification does not change when the object is moved on the optical axis. Therefore, the resulting image will always be the same size regardless of the distance to the object.
Measurement lenses use this characteristic to allow for a certain tolerance regarding the distance and position of the parts to be measured. The TD series provides minimal distortion along with extremely high resolution, allowing users to greatly improve their measuring accuracy. At a 16 Megapixel resolution, the maximum field of vision for a 36 x 24mm sensor is 150 x 100mm.