Sunday, December 23, 2007

HD Jargon Buster

Don’t let ‘technical jargon’ stop you joining the HDTV revolution! Our no-nonsense guide to the common terms used will help you to understand all you need to know to enjoy an intense viewing experience.

720-line HD

The 720-line system is the most common format for the launch of HD television. The 720-line system is 1280 pixels across, so the resolution is 1280 x 720, giving just over twice the resolution of a 625-line standard definition picture.

1080-line HD

The 1080-line system is the other common HD format. A 1080-line system has 1080 vertical pixels and 1920 horizontal pixels, with up to five times the resolution of a standard definition picture.

Aspect Ratio

This refers to the ratio of a pictures width relative to it’s height. The aspect ratio of a standard television is 4:3, whereas HDTV has an aspect ratio of 16:9, for a more intense viewing experience. The more common names for aspect ratio are ‘Widescreen’ or ‘Letter-box’.


Also known as ‘Dolby Digital’ this is the 5.1-channel sound system specified in the Standard for Digital HDTV, delivering CD quality digital audio from six speakers, front left, right and centre (where most of the ‘voice’ comes from), rear left and right plus a subwoofer for depth, to produce a cinematic sound! True 5.1-channel sound is only available via a home cinema system

Bit Rate

‘Bits per second’ or bps, expresses the rate at which data is transmitted. Generally, the higher the bit rate, the better the image and sound quality.


Expressed as candelas per square metre (cd/m2) brightness simply indicates how much light is emitted by the screen. A higher candela means a brighter picture.

Component Video

Three connectors (usually red, green and blue RCA jacks) that transmit and receive component video signals. The combination of these signals conveys all the picture information.

Contrast Ratio

Essentially contrast ratio is a comparison of a screens blackest black and whitest white.A higher contast ratio indicates that on screen colours will be richer.


Digital Video Interface. DVI is a type of cable connector which provides a high-bandwidth connection between a video source and a display device.


Electronic Programme Guide. An onscreen display of channels and programme data.


High Definition Multimedia Interface is a digital connection for video/audio data. It ensures a high-quality video signal is delivered to your display via a single cable.


This is a copyright protection system that is incorporated into HD receivers and displays. It stands for High definition Digital Content Protection and prevents unauthorised use of content which is copyrighted.


Liquid Crystal Displays are flat-panel televisions designed to offer superior images. A liquid crystal solution is sandwiched between two panels and electrified. This causes the crystals to act as ‘shutters’, some allowing light to pass through, other blocking light out. These ‘shutters’ on the electrified crystals form the image on the LCD TV.


A pixel is literally a single dot on the screen and the pixels form the image on your display. The more pixels, the better the picture. With HDTV there are many more pixels (typically 1920 x 1080 or 1280 x 720) than with Standard Definition TV (720 x 576), giving a crisper, clearer and sharper picture.

Plasma Display

A compatible plasma TV is one way to display HDTV. The image is created by hundreds of thousands of tiny cells filled by ionized gas in a plasma state.


The measure of the amount of detail an image can show. HD has a maximum resolution of 1920 x 1080 which equates to 2,073,000 pixels whereas standard definition has a resolution of 720 x 576. The higher the resolution – the better the resulting image.

Standard Definition (SDTV)

This is the traditional definition television system, currently used. A standard definition picture is 720 x 576 pixels.

Viewing Angle

LCDs were originally designed as computer monitors, and as such were designed for head on viewing. Viewed at an angle these early screens lost much of their contrast and brightness. In response to this manufacturers are continually increasing viewing angles for LCDs where the quality is retained. Viewing angles as high as 176 degrees are now being achieved.

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