Auto Iris Lense

Auto-Iris
Lenses for CCTV Body cameras are also available
as "Auto-Iris" types. These have a lead that connects
to the camera itself, and provides the camera with the
ability to let in more light in dark conditions, and
less in bright conditions. This helps avoid the common
problem of "sunrise glare", where the rising sun shines
directly into the camera, completely blinding the camera's view.
Auto-Iris lenses are available as two types,
DC-Drive and Video Drive. DC-Drive lenses use a control signal
from the camera to adjust the iris size, whereas video-drive
lenses adjust the iris size based on the brightness of the
image in the video signal.
Lenses are either DC drive or Video Drive, but never both.
Cameras very often support both modes, utilising a mini switch
to select which to use, but not all camera Video Drive
With a video driven lens, the video signal is picked up from
the AI connector, which is connected to the camera. Because the
lens adjust the iris based on the video signal, the lens is
referred to as a video drive lens.