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Technical Glossary
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Data Projector
A device that displays a PC's output on a large screen for presentations and demonstrations.
DC
Stands for direct current. This is an electric current that never reverses its direction of flow (polarity). Practically all electronic equipment and computer hardware needs DC to function.
DECK
A group of data processing cards. It also means a recorder/player, for example, a video tape deck.
Depth of Field
This describes what is in focus in front of, and behind, the object on which the lens is focused.
Digital
This is information in the form of binary data. Computers use a binary system. Binary is represented by '0' (off or non-positive) and '1' (on or positive). The digital data which is stored or transmitted is expressed as a series, or string of zeros and ones.
Digital 8
Uses the same compression and editing protocols as DV. Digital 8 records video using DV compression onto Video8 orHi8 tapes, but running up to twice their normal speed.
Digital Video
Video recorded in binary form. Digital video allows material recorded on a digital video camcorder to be transferred to a computer, edited and then delivered in a variety of different formats, including the re-streaming of material back to the camera with no loss of quality.
Digital Video Pilot
50 schools from across the UK took part in Becta's digital video pilot, which ran from October 2001 to March 2002. Schools were given a iMac, a digital video camera, iMovie 2 and quick time pro licenses. The pilot aimed to gather evidence on the impact of use of digital video technology on pupil engagement and behaviors. It also aimed to identify models of effective practice in inspiring and developing pupil's work with digital video. Find out more: http://www.becta.org.uk/dvpilot
Digitise
To convert analogue video or audio to a digital format.
DV
Short for digital video. DV also stands for a type of compression used by DV systems or a format that involves DV compression.
DV in
Means 'Digital Video in'. Digital video cameras need this input to be able to record digital video from a computer or other external source, and some software also uses it to control the video camera. Many European cameras can record a DV-signal, but the DV-in has been deactivated to avoid the payment of EC duty on video recorders. This means unless they are subsequently modified, these cameras can only play video out, for example to a video recorder or a computer rather than recording it.
DV out
Means 'digital video in'. Normally, if a camera is advertised as 'DV out', it means that it will not accept DV in.
DVD
Stands for digital versatile disc, a high-density disc for storing large amounts of data, especially high-resolution audio-visual material. More material can be stored on a DVD that on a CD-ROM.