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Video Notes
Camcorder Controls
Videomaker's Glossary
NTSC stands for National Television Standards Committee. The NTSC is responsible for setting television and video standards in the United States (in Europe and the rest of the world, the dominant television standards are PAL and SECAM). The NTSC standard for television defines a composite video signal with a refresh rate of 60 half-frames (interlaced) per second. Each frame contains 525 lines and can contain 16 million different colors.
The NTSC standard is incompatible with most computer video standards, which generally use RGB video signals. However, you can insert special video adapters into your computer that convert NTSC signals into computer video signals and vice versa.
Composite is a type of video signal in which all information -- the red, blue, and green signals (and sometimes audio signals as well) -- are mixed together. This is the type of signal used by televisions in the United States
Super-Video is a technology for transmitting video signals over a cable by dividing the video information into two separate signals: one for color (chrominance), and the other for brightness (luminance). When sent to a television, this produces sharper images than composite video , where the video information is transmitted as a single signal over one wire. This is because televisions are designed to display separate Luminance (Y) and Chrominance (C) signals. (The terms Y/C video and S-Video are the same.)
Computer monitors, on the other hand, are designed for RGB signals. Most digital video devices, such as digital cameras and game machines, produce video in RGB format. The images look best, therefore, when output on a computer monitor.
Video Cables
The four main types of cable common to video are RF, Composite, S-video and IEEE 1394 or FireWire.
Radio Frequency or RF cable sends both audio and video down a single wire. The quality is not very good. This is the type of cable used by cable TV.
Composite or RCA cable carries a mixture of the luminance (black-and-white) and chrominance (color) information. It consists of two separate wires in one casing running parallel. The power wire corresponds to the tip of the connector and the ground wire links to the outside ring.
Composite cables with three cables bound together, with yellow ,red and white tips carry composite video and stereo audio.
S-video cables are also know as Y/C (Y for luminance and C for chrominance). The separation of black-and -white and color signals is what makes S-video better than composite. S-video wire consists of two pairs of wires. S-video wires cannot exceed 25 feet in length.
IEEE 1394 cable is also known as FireWire or i.LINK. It transmits digital video signals and supports data transfer rates of up to 400 Mbps (400 million bits per second). FireWire cables are limited to 4.5 meters or about 14 feet without a repeater. A FireWire cable can have either a six or four pin connectors. Digital camcorders use the four-pin configuration, while Macintosh computers use the six-pin configuration.
Last Update:
February 28, 2005
Yannis Grammatis
