Designed for machine vision applications, the TEC-M40110MP 4.0x 2MP Telecentric C-Mount Lens from computar is compatible with 2MP 2/3" sensors. It has a working distance of 4.35", 4.0x magnification, and low corner distortion of -0.004% maximum.
Telecentric lenses are designed so that light exiting the rear element is perpendicular to the sensor. Non-telecentric lens design allows light to strike the sensor at an angle, which can lead to vignetting at the edge and corners of the sensor. The telecentric design minimizes vignetting.