Basic CCTV Terminology
MECHANICAL FOCUS
Focusing of a camera lens or
MONOCHROME
Black and white picture comprising of a number of levels of grey scales.
MULTIPLEX
Method of transmitting or recording many video signals at the same time.
ND
Neutral Density. Filter which is positioned on the rear of the lens, enabling the camera to operate in difficult lighting conditions, by widening its operating parameters.
PEAK TO PEAK
Value between the maximum positive and negative points on a waveform.
PIXEL
A word derived from Picture Element. This is the smallest unique point of digital video image. In digital video, a picture is divided up into thousands of Pixels, each specified by luminance, chrominance and position information.
REAL ACTION RECORDING
High density VCR recording which provides three times as many fields as conventional
RESOLUTION
The definition of a TV picture in terms of the finest detail that can be recorded and played back.
RS232/485
Serial Interface commonly used to commu- nicate between different control equipment.
SMART CONTROL
Developed by Sony in 1994, this digital technology allows Sony cameras to automatically adjust iris, gain, white balance and flicker to external lighting conditions.
SEQUENCE SWITCHER
A switcher that displays camera pictures in a set order and dwell time, predetermined by the user.
SPECTRAL RESPONSE
This is the response of the light sensing (charge coupled) device to different
wavelengths of light. Typically between the ultra violet and
SYNC GENERATOR
Device that produces a synchronisation signal.
SUPER-VHS
VCR recording system that enables recording of 400 TV lines horizontal resolution as compared with ordinary VHS of 240 TV lines.
TELEMETRY
Electronic method of controlling functions, such as pan, tilt, zoom, focus, generally via coaxial cable or a twisted pair of fibre optic.
TIME LAPSE
Video cassette recorder which allows the compression of real time recordings onto tape using time lapse mode. Can be up to 960 hours onto a single hour tape.
TRINITRON CRT
Cathode Ray Tube which is completely flat in the vertical plane to enable better monitor image geometry.
TRIPLE MULTIPLEX
A transmission of video, sync and DC power over a single coaxial cable.
VERTICAL PHASE
Feature on some AC cameras to adjust line lock and synchronise
VHS
Video Home System domestic video recorder format giving 240 TV lines horizontal resolution.
WATERMARKING
Technical method of ensuring the integrity of images recorded digitally.
WHITE BALANCE
Term which only applies to colour cameras. Where white is the reference to determine all other colours in the visible spectrum.
Y/C
Method of separating and transmitting video signals divided into Chrominance C (colour) and Luminance Y (brightness) for higher resolution and quality. Usually employed between multiplexer/recorder/monitor.
ZOOM RATIO
Term where the lens has moveable elements. For example it is generally defined as 6:1 or 10:1 (i.e. 12.5 – 75mm or 10 – 100mm)
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The Sony Guide to CCTV . Issue 3