A Guide to the jargon that surrounds High Definition Television
Know your plasma from your LCD or your 1080p from your 720p with our guide to all the jargon and 'sales speak'.
1080i: The name given to the HDTV (high definition) standard most commonly available. This delivers digital video
with a resolution of 1920 by 1080 pixels (1920 x 1080), or 1440 by 1080 pixels (1440 x 1080), in what is known
as interlaced format.
1080p: The video standard used for Blu-ray format, the highest quality currently available. This provides 1920 by 1080
pixel resolution (1920 x 1080) normally at 24 or 60 frames per second.
720p: A high definition digital video format where the image has a width of 1280 pixels and is 720 pixels tall (1280 X 720).
The video is in progressive scan format and can be delivered either 50 times per second or 60 times per second.
Aspect ratio: The width of a picture relative to its height. Analog pictures have a 4:3 aspect ratio, while high definition displays such as projectors, plasmas, LCD TVs and HD broadcasts have a 16:9 aspect ratio.
Blu-ray: The successor to the DVD, this format has nearly six times the capacity of a DVD providing the best in-home video entertainment. That said, it is currently battling it out with the HD-DVD format. Sony, which backed the Blu-ray high definition DVD format by building it into its PlayStation 3 games
consoles, squares up against Toshiba, backed by Microsoft and Intel, promoting the rival HD DVD format.
Contrast ratio: The range of brightness between the deepest blacks and brightest whites of a TV screen. Usually this gives a good indication of how black a screen can go. The higher the number the better.
Dolby Digital: A digital audio format for carrying high quality surround sound,with up to 5.1 channels that is used on DVDs, Blu-ray and HDTVs.
DTV (Digital television): A term referring to all digital television formats, including high definition television (HDTV) and standard definition television (SDTV).
HD (High Definition): A detailed video format with a resolution of 1280 by 720 pixels or more commonly 1920 by 1080 pixels.
HDTV (High Definition Digital television): A term referring to the highest quality digital television format currently available, providing greater sharpness and detail than the standard definition television (SDTV).
HDMI (High-Definition Multimedia Interface): A connection standard for delivering high quality digital video and audio between devices in a single cable.
Integrated TV: Any display, such as an LCD or plasma, that integrates a standard definition or high definition digital television tuner.
Interlaced: The opposite of progressive scan. Video and film consists of a series of still images shown in quick succession. When interlaced, each still image (or 'frame') is broken into two parts each called a field and these fields are sent in succession. When video is interlaced, it is up to the display to
recreate the full frames from the two fields. The letter 'i' is often used to indicate this, for example '1080i'.
LCD (Liquid Crystal Display): A display technology used in TVs and projectors. LCD panels control the light that can pass through them producing the picture.
NTSC: TV system used in the United States, Japan and South Korea. A frame of NTSC video is made of 480 horizontal lines but broken into two 240-line fields which are sent in sequence, sixty times per second. The digital version of this on DVDs has a resolution of 720 pixels across by 480 pixels tall.
PAL: TV system used in the UK, much of Europe, Australia and various Asian countries. A frame of PAL video is made up of 576 horizontal lines but broken into two 288-line fields that are sent in sequence, 50 times per second. The digital version of this on DVDs and SDTV has a resolution of 720 pixels across by 576 pixels tall.
Pixel: Short for 'picture element'. This is a group of three tiny dots (red, green and blue) that form a single coloured dot. The picture consists of hundreds of thousands of these coloured dots arranged in a grid.
Plasma: A display technology used for panel displays. The picture is created by an array of tiny glass cells which contain a certain gas. When an electrical signal is applied the gas emits ultraviolet light that excites coloured phosphors in the cell to emit coloured light.
Progressive scan: The opposite of interlaced. Video and film consists of a series of still images shown in rapid succession. With progressive scan the entire still image (frame), is transmitted intact. The letter 'p' is often used to indicate this, such as '1080p' and '720p'.
Resolution: A measurement of the detail that can be displayed in a video image. Resolution is commonly determined by the number of horizontal lines (measured vertically) used to create the image, with higher numbers indicating more detailed images.
SD (Standard Definition): The standard picture resolution similar to that seen on DVD. This has a resolution of 720 by 576 pixels (720 x 576).
Viewing Angle: LCDs were originally designed as computer monitors,and as such were designed for head on viewing. Viewed at an angle the early screens lost much of their contrast and brightness. Manufacturers are continually increasing viewing angles for LCDs to ensure the quality is retained. Viewing angles as high as 176 degrees are now being achieved with the latest models.
See also: LCD or Plasma? | Best Brands?
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