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Glossary of Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 

AGC

Automatic Gain Control is an electronic circuit that amplifies the video signal when the strength of the signal falls below a certain value.

Angle of View

May be expressed in Diagonal, Horizontal or Vertical. Smaller focal lengths give a wider angle of view.

Aspect Ratio

The ratio of width to height for the frame of the televised picture. 4:3 for standard systems

Back Focus

A mechanical adjustment in a camera that moves the imaging device relative to the lens to compensate for different back focal lengths of lenses. An important adjustment when a zoom lens is fitted.

Camera Format

The approximate size of a camera image pickup device. This measurement is derived from the diagonal line of a chip. Common formats are 1/6 in, 1/4 in, 1/3 in, 2/3 in and 1 in.

Day/Night (Digital)

Digital day/night (also referred to as electronic day/night) improves low light sensitivity, delivers a sharper image in low light conditions, and enables the camera to see in the dark without the help of external IR illuminators. Unlike true day/night cameras, which use a mechanical filter, the camera electronically adjusts colors during the day instead of using an infrared filter. This allows the digital day/night cameras to deliver similar benefits of true day/night cameras, but at a lower cost. Without the need for a physical filter, digital day/night technology can be leveraged for smaller form factors, such as bullet cameras.

Day/Night (True)

True day/night (also referred to as mechanical day/night) improves low light sensitivity, delivers a sharper image in low light conditions, and enables the camera to see in the dark without the help of external IR illuminators. To accomplish this, the camera automatically removes the infrared filter from in front of the CCD chip which enables the camera to see near infrared light, and allows more light into the imager to deliver a clearer picture and minimize distortion when in black and white mode.

EIA

Electronic Industries Alliance. Monochrome video signal standard used in North America and Japan: 525 lines 60Hz

Equalizer

An electronic circuit that introduces compensation for frequency discriminative effects of elements within the television system, particularly long coaxial transmission systems.