derek kemp audio visual


Common Audio Visual & Information and Computing Technology Terms

ANSI Lumens - One way of measuring the light output from a projector, not infallible as contrast is as important to perceived image quality, take all figures with bucket of salt

Bandwidth - In simple terms the amount of information a system is capable of transmitting, in detail, how long have you got?

Candela or CD/m2- a measurement of how bright a screen is, methods of calculation & test vary so more salt to be taken

Cat5 (also Cat5e, Cat6, etc) - cabling standard for network cabling, cheap, everywhere, really fiddly to make up connectors for

Component video - Higher connection standard with a separate wire for three “components” of the video signal, better than composite or S-video

CODEC - Coder / Decoder a device found in video conference units and your PC to compress and decompress data, usually video for transmission

Digital Audio - You can “steer” audio around a space, you can send it over networks and you can create and edit it on a PC, clever

Digital signage - fashionable term coined by display companies keen to surround you with screens.

DLP / DMD - Projection technology alternative to LCD, uses gazillions of tiny mirrors flapping around to shine reflected light from a bulb, wow!

DVI - Digital Visual Interface, usually the best quality connection between player and display, sadly available in many flavours HDMI etc to confuse

Gain - often used to describe the amount of light a screen delivers to the viewer, never quoted against white emulsion which can be surprisingly cost effective

HDR - Hard Drive Recorder, those clever boxes that have replaced VHS tape as the easiest way to record just about anything

High Definition TV - New video standard for better quality images on TVs or other displays. HD Ready and True HD are NOT the same, a display that accepts a high quality signal may not actually display that quality, ask the dealer

IEEE1394 - Yet another connection standard often between PCs & video devices also known as Firewire, I-Link

Interactive - the need to press buttons to get the information you want, not always for the better

Interface - black box to join square pegs to round holes, should be redundant when signals are standardised, aye right

IP - Internet Protocol, now being stuck in front of video, audio, control etc meaning you can send most things over an ethernet network now

Induction loop - A system for providing enhanced listening to hearing aid users, important for DDA compliance, don’t just put one in, try listening to it

Keystone - The funny shapes you get when a projector is not lined up correctly, some projectors now fix it for you, better to move the projector

LCD / Plasma - Two competing technologies for flat panel displays. Pros & cons for both but LCD gaining ground

LED - new long life light source coming to many lights and soon projectors

LED screen - Usually used for big outdoor video screens, pricey but bright

MP3 - The file format used in your Ipod and other music players, not best quality but ubiquitous

Resolution - The amount of detail available in an image, complex subject with many different types of measurement

Reverberation - Sounds bouncing around, good for some styles of music, bad for video conference or speech intelligibility

Pixel - Picture element, the small dots that make up most video images, the more you have the better the picture as a rule

Source - Any player device that is part of a bigger system

State of the Art - Client’s aspiration, rarely defined or matched by available budget

Throw - The distance needed between a projectors lens and the screen for a given image size, always too much for space planners, never enough for technicians

Videoconference - Like a telephone call but with pictures, much improved quality in recent years, better than a day in a budget airline

Zone - Teccy word for room usually, used to define systems that can send audio and video to different rooms, sorry zones

16:9 - Aspect ratio of widescreen tellies, as opposed to older 4:3 shape, other variations for cinema, WXGA etc

WXGA, VGA, SXGA UXGA etc - numbers of pixels in an image such as VGA 640 x 480 (not many these days) or UXGA 1600 x 1200 (pretty decent)

3D - the promise of a thrill ride in your living room, its getting better but the specs are not groovy yet


Still confused? Call dkav on 01620 861 100


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