Explanation of different lenses:

Auto Iris Lens A lens in which the iris aperture automatically opens or closes to maintain proper light levels on the face-plate of the camera pickup device.

Video Type Auto Iris Lens An auto iris lens with internal circuit which receives voltage and a video signal from the camera to adjust the iris.

DC Type Auto Iris Lens An auto iris lens without an internal circuit to control the iris. All iris control voltages come from a circuit located within the camera.

Manual Iris Lens A lens with a manual adjustment to set the iris opening (F stop) in a fixed position. Generally used for fixed lighting applications.

Angle of View The angular range that can be focused within the image size. Small focal lengths give a wide angle of view and large focal lengths give a narrow field of view.

F-Stop A term used to indicate the speed of a lens. The smaller the f-number, the greater is the amount of light passing through the lens.