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Technical Glossary
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AC
Stands of alternating current. This is an electric current that reverses its direction of flow (polarity) periodically according to a frequency measured in hertz, or cycles per second.
ADC
An analogue-to-digital converter. This converts analogue signals into digital signals for subsequent processing. To be stored on a computer, analogue video must be converted to digital video.
AGP
An abbreviation for accelerated graphics port. It is an interface specification that enables 3-D graphics to display quickly on ordinary personal computers.
Analogue
Refers to electronic transmission which is achieved by adding signals of varying frequency or amplitude. For example, a vinyl record stores sound as an analogue signal, while a CD is digital. Broadcast (television) and phone transmission have traditionally used analogue, although digital is now becoming more widely used. To be stored on a computer, analogue video must be converted to digital video.
Animation
A series of still images which are recorded in a sequence to make them appear to move on film.
Aperture
This is the opening which controls the amount of light passing through the lens. It is expressed as a fraction of the focal length, so that a lens with an aperture of 11.4 lets in more light than one with an aperture of f2.0. In general, a 'faster' lens (one with a wider maximum aperture) will be better for filming in low light.
AVI
Stands for audio-video interleaved and this is the file format for saving video used by Microsoft windows.