CCTV Glossary

Alarming -- Feature on some CCTV equipment which allows the equipment to provide a simple switch closure (usually) in response to a designated input alarm signal.

Aperture Opening (Lens) -- Controls the amount of light reaching the surface of the camera pick-up device. Aperture size is controlled by the iris. Increasing the f-stop decreases the amount of light reaching the pick-up device.

Aspect Ratio -- Ratio of picture height to picture width. Standard ratio is 4:3.

Automatic Brightness Control -- Electronic circuitry which automatically controls the brightness of video monitors in relation to ambient light.

Automatic Frequency Control (AFC) -- Circuitry that automatically maintains the desired frequency.

Automatic Gain Control (AGC) -- Circuitry that automatically adjust the signal to proper strength.

Automatic Light Control -- Process by which the brightness upon the camera pick-up device is automatically adjusted according to the brightness of the scene.

Auto Pan -- Automatic back and forth camera motion

Auto Scan -- Same as Auto Pan

Auto Iris Lens -- Camera lens which automatically adjust for proper light levels

Attenuation -- A decrease in signal strength.