1/3" 2.9-8.2mm f 1.0 Varifocal, DC Auto Iris (CS Mount) Computar Lense for 1/3 type Cameras, Vari focal Auto Iris DC Drive Computar varifocal DC auto iris lenses offer maximum flexibility in camera installations requiring a wide range of focal lengths. Focal length adjustments can be made with a turn of the dial, virtually eliminating the cost..