Which of the following is not a true statement about CCTV lenses?

A.
Lenses that have a manual iris should be used in outside monitoring.

B.
Zoom lenses will carry out focus functionality automatically.

C.
Depth of field increases as the size of the lens opening decreases.

D.
Depth of field increases as the focal length of the lens decreases.

Explanation:
A: Manual iris lenses have a ring around the CCTV lens that can be manually turned and controlled. A lens that has a manual iris would be used in an area that has fixed lighting, since the iris cannot self-adjust to changes of light. An auto iris lens should be used in environments where the light changes, such as an outdoor setting. As the environment brightens, this is sensed by the iris, which automatically adjusts itself. Security personnel will configure the CCTV to have a specific fixed exposure value, which the iris is responsible for maintaining. The other answers are true.