Commercial object-space telecentric lenses are often characterized by their magnification, working distance and maximum image circle or image sensor size. A truly telecentric lens has no focus ring to adjust the position of the focal plane. Some commercial telecentric lenses, however, do feature a focus ring. This can be used to slightly adjust the working distance and magnification while losing a little bit of telecentricity. Sometimes, manufacturers specify a sensor resolution or pixel size to describe the optical quality of the lens and the maximum optical resolution it can achieve due to the lens's aberrations.
