Glossary

GLOSSARY OF TERMS

Auto Iris Lens - A lens with a mechanical iris which is controlled by a motor or other electrical device and responds to the changing video levels produces by a camera.  The iris will be driven more open as the light hitting the image device becomes less and less and vice versa with an increase in light.  The lens automatically adjusts the amount of light reaching the imager.

Auto Sequencing - The automatic viewing of each image within a quad processor, one after another.

Automatic Brightness Control – In display devices, the self- acting mechanism which controls brightness of the device as a function on ambient light.

Automatic Gain Control – A function that automatically adjusts the brightness level of video, to keep it consistent.

BNC (Bayonet Network Control) – A type of connector/cable end used primarily for video and CCTV

Coaxial cable – a special type of wire used to carry low voltage signals.  It gets its name from having two conductors configured in concentric circles or two conductors having the same axis. The center conductor is a solid or stranded wire running the full length of the cable.  The second conductor is constructed in a braided fashion around a separating non-conductive material. This material is called the dielectric.  Coaxial cables have a rating called impedance which is a measurement of resistance and capacitance, the rating for cable used in the CCTV industry is 70 Ohm.

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CCD (Charge Coupling Devices) – A light sensor that is employed by scanners and digital cameras to convert analog data into digital data.

CCTV - A common abbreviation for Closed-Circuit Television.

Digital Recording - A computer term associated with storing electronic files to disk, which can include video, audio or data files.  The process used by a digital video recorder (DVR).

Digital Zoom – A function that creates an electronic zooming effect by ‘blowing the image up’.

Field of View - The width and height or area desired to be covered by one camera.  This area is determined by the focal length of the lens on the camera and the distance the camera is mounted from the scene.

GB (Gigabyte) – One gigabyte is equal to 1,024 megabytes.  It has the storage capacity of approximately 1000 floppy disks.

HDD (High Density Disk – aka Hard Drive) - The device onto which digital data is stored – similar to what is inside your home computer. It is the standard specification for most electronic storage devices today.

Illumination – The amount of light cast on an object.

IP55 Water Resistant – A standard by which products are tested against dust and water.  IP55 means that products will be sealed and protected against a typical spray of dust or water.

IR (Infrared) – A wave that is part of the electromagnetic spectrum that is very close to light, but invisible to the human eye, often called night vision.

Iris – the “eye” of the camera

Looping – Referring to the video inputs on a device such as a switcher of quad.  The input is not terminated and has provisions to continue the video line; normally two BNC connectors are present on the rear of the device making it possible to connect the video signal to additional devices.  The looping of a video signal should be limited to a few devices.

Lux – A measurement for the amount of illumination on an object.  The lower the number, the better the image will be at night.

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MB (Megabyte) – A device that allows multiple logical signals to be transmitted simultaneously across a single physical channel.  This allows you to add more camera images to single or quad capable monitors.

Optical Zoom – a function that magnifies the size of an image by adjusting the focal length of the lens.

PIR (Passive Infra Red) – A function that monitors changes in heat to determine motion.  In essence, a heat driven motion sensor.

Pixel – a tiny sample of video information, the “dots” that make up an overall picture.

PPP (Point – to – Point Protocol) – Software, that allows for communication from modem to modem.

Quad Processor – A function that allows up to 4 images to be displayed via 4 separate video sources.

Resolution – A measure of graphics that’s used to describe what a printer, a scanner can scan and a monitor can display.  The higher the resolution number, in general, the better the picture quality will be.

RJ12 – A type of cable and connector.  It supplies power, audio and video within the same cable.

Secondary Monitor – A second monitor that connects to your primary monitor, which allows you to view the same picture on both.

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TCP/IP – A format for networks that assigns numbers to devices, which allows them to be unique.

Variable Dwell Time – On a monitor, it is the amount of time delay between the switching of images.

VariFocal - A function that provides the ability to change the focal length of a camera manually.

Video Transmitters – A device that transmits video across phone lines or the Internet.