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Find a list of the most used words in the CCTV world, and there meaning. If you think a word is missing on the list, you are more than welcome to contact us about it. [Do not edit this line] Aperture Number of lense (F) The aperture number of the lens is the index of the theoretical light gathering power of the lens, expressed as the ratio of the effective diameter of the lens (entrance pupil) to the focal lengths Aspect ratio The aspect ratio of a camera picture is the width to height ratio of the sensitive area on the imaging device that is used to form a camera picture Auto Pan Function A function that allows automatic panning between adjustable limits Automatic Black Circuit An optional circuit in the camera that brings the darkest part in the scene to black level Automatic Iris A mechanism for controlling the iris of the lens in relation to the scene illumination depending on the video signal Automatic Light Control An optional circuit in the camera that automatically adjusts the camera sensitivity to changing light conditions in order to maintain the composite video output signal within define limits Back Focus Back focus is the distance between the external surface of the lens which is closest to the imaging device (last lens vertex), and the focal point Black Level The electrical signal level in a composite video signal representing optical black Blanking Level The electrical signal level in a composite video signal of the front and back porch of the synchronising signal Camera Housing An enclosure to provide physical and/or environmental protection of the camera, lens and ancillary equipment Camera Sensitivity Imaging device illumination necessary to produce a define composite video signal amplitude with a defined signal to noise ratio CCIR Comité Consultatif International des Radiocommunication CCTV Camera A unit containing an imaging device producing a video signal from an optical image CCTV Control Unit Equipment for controlling and monitoring the required operational functions of the CCTV system CCTV Surveillance An installation consisting of the components of a CCTV surveillance system with all necessary hardware and all necessary software, fully installed and operational for monitoring a defined security zone CCTV Surveillance System A system consisting of camera equipment, monitoring and associated equipment for transmission and controlling purposes, which may be necessary for surveillance of a defined security zone Character Generator A device for generating alpha numeric characters and/or symbols and adding them into the image Composite Colour Video Signal (CCVS) The composite colour video signal of a colour camera comprises the burst and colour information (colour) and picture luminance component (video), blanking and the synchronisation components (synchronisation). Composite Video Signal (CVS) The composite video signal of a b/w camera comprises the picture component black reference and the synchronisation components Depth of Focus Depth of focus is the range of distances from a CCTV camera over which the image appears acceptably sharp Electronic Iris An automatic electronic shutter which varies the camera sensitivity in relation to the various light conditions in order to maintain the video output signal within defined limits Electronic Shutter An arrangement in the camera changing its sensitivity by electronically controlling its exposure time Event Recording The event controlled recording or storing of image signals for a pre-determined time External Synchronisation A method of feeding reference timing signals to all connected devices to ensure that their video output signals are synchronous Filter Mount The attachment point of a lens for mounting an optical filter Fixed Focal Length Lens A lens with one defined focal length Flange Back Distance The distance between the surface of the lens mount flange to the focal point Focal Lenght (f) A property of a lens, expressed in mm, giving the angle of view for a given sensor size Focusing Mechanism of the Lens A mechanism on the lens enabling correct focus of objects at various distances from the CCTV camera Gamma Correction Non-linear signal processing that establishes correct grey scale reproduction on the picture tube Genlock Synchronising of the camera’s horisontal and vertical frequencies, adjusted to an external compounded signal Image Sensor A device that converts an optical image into an electrical signal Image Sensor Illumination The level of illuminance at the photosensitive surface of the imaging device * Image Sensor Size An expression for the size of the light sensitive surface of the imaging device. The value is expressed in inches and refers to the diameter of the glass tube from which the camera tubes were constructed.Some examples of the sizes are:
Iris Lens A lens is an optical device for projecting an image of a desired scene onto the photo sensitive surface of the imaging device Lens Mount The mechanical interface between the lens and the camera Local CCTV Control Unit A CCTV control unit for controlling and/or monitoring part of the overall CCTV system Manual Iris A mechanism for manually adjusting the iris of the lens Motorised Iris A motor driven mechanism on the lens for adjusting the iris ND-Filter Iris An iris whose segments include neutral density filters with graded density for further reducing the optical transmission of the lens beyond that achievable by normal closing of the iris Optical Filter A device that modifies specific optical properties of the light passing through it (e.g. spectral properties, image quality properties) Optical Focus The position of the focusing mechanism of a lens that gives the sharpest image of the desired object Pan and Tilt Unit A motorised unit permitting the vertical and horizontal positioning of the camera equipment Pan Unit A motorised unit permitting horizontal positioning of the camera equipment Picture Signal The part of the composite video signal that contains the picture information Picture Storage The storing of video images Pinhole Lens A specialised lens with a small entrance pupil for surveillance through a very small orifice Pixel An acronym for picture element, which is the smallest sample of an image.This sample may be a discrete sample produced by a solid state imaging device, or by a digitised sample Preset Function A function in pan and tilt units and/or Zoom lenses, which allows automatic return to one or more predetermined positions Ramping A characteristic of some zoom lenses whereby the effective aperture of the lens decreases as the focal length is increased Remote Controlled Camera Equipment Devices for controlling the functions of camera and ancillary equipment via remote control signals Scene Brightness The observed brightness of an object in the scene, dependent on the scene illumination and scene reflectance Variabel Focal Lenght Lens A lens with adjustable focal length, in which the image of the scene does not remain in focus as the focal length is changed Vertical Interval Switching Controlled switching between video inputs during the vertical retrace time Video Amplifier A device for amplifying the video signal level Video Distribution Ampilfier A device which provides multiple video outputs from one video input Video Equalising Amplifier Equipment for correcting gain and frequency related distortions in the video signal Video Matrix A unit for connecting several input video signals to several outputs Video Memory Equipment for electronic storage of one or more video images Video Monitor A device for converting video signals into pictures on a display screen Video Motion Detector Equipment for generating an alarm condition in response to a change of the contents of a given image Video Multiple Image Unit Equipment for combining and displaying several complete pictures simultaneously on a single monitor Video Printer Equipment for converting a video signal into an image on paper Video Switcher A unit for switching a number of video input signals to one or more outputs manually or automatically or on receipt of an external signal White Clipper A circuit within a camera limiting the maximum white excursions of the video output signal to a defined level Zoom Lens A lens with adjustable focal length, in which the image of the scene remains in focus as the focal length is changed |