DARK CURRENT
Leakage signal from a CCD sensor in the absence of incident light.
DARK NOISE
Noise caused by the random (quantum) nature of the dark current.
DECIBEL (DB)
A logarithmic ratio between two electrical signals or values. Usually refers to power, but can also be used for voltage and current.
DC
Direct Current.
DE-MULTIPLEXING
The process of separating different video, audio, or data signals, which were multiplexed at source.
DEPTH OF FIELD
The distance between the nearest and furthermost object in a scene which appear in sharp focus. Depth of field varies depending on the f-stop and focal length of a lens. Depth of field increases when the f-stop is greater, the focal length shorter or the distance to the object is increased.
DIELECTRIC
An insulating (non-conductive) material. Found between the inner core and outer shield of a co-axial cable.
DIGITAL SIGNAL
An electronic signal, which is represented by binary numbers, and that, can be processed by a microprocessor, or stored in an electronic memory.
DOME
Term used to describe a type of camera housing made of...