S

SaBRE (Subtractive Bi-Refringent Effect)

A technology that allows two panels rather than three to generate the full 16 color VGA palette. The top panel provides white, magenta, blue, and cyan; the second brings colors from white through yellow and to red. [Projector People]

Sample

A digital value derived from measuring a discrete part of an analog original. See sampling. [Getty]

Sampling

The mechanism by which analog signals or objects are digitized. Sampling involves dividing an analog whole into regularly spaced, smaller discrete components, measuring the values of each such component, and converting these measurements to binary code. Provided enough samples are taken, the readings create the illusion of a continuous (i.e., analog) signal or object when decoded.[Getty]

Saturation (Chroma, Chroma Gain, Color)

1. The intensity of the colors in the active picture. The voltage levels of colors. The degree by which the eye perceives a color as departing from a gray or white scale of the same brightness. A 100% saturated color does not contain any white; adding white reduces saturation. In NTSC and PAL video signals, the color saturation at any particular instant in the picture is conveyed by the corresponding instantaneous amplitude of the active video subcarrier. 2. The point on the operational curve of an amplifier at which an increase in input amplitude will no longer result in an increase in amplitude at the output. [BAVC]

Scan

In data processing, image scanning is to optically analyze a two or three dimensional image and digitally encode it (digitize it) for storage in a computer file.[EAI]

Scanning

The rapid movement of the electron beam in a pickup device of a camera or in the CRT of a television receiver. It is formatted in a line-for-line manner across the photo sensitive surface which produces or reproduces the video picture. [BAVC]

Scanning line rate

The U.S. TV NTSC Standard since the 1940s uses a scanning rate of 525 lines per frame. Each frame (picture) is scanned twice at 262.5 lines per scan. The second scan is in between, or interlaced, the lines of the first scan. This complex system saves valuable frequency bandwidth. Computers do not have the problem faced by limited airwave bandwidth so conventional computer monitors use progressive scanning at 30 or 60 fps with no interlace. [AMIA]

Scart cable

A scart cable is a 21-pin connector for connecting audio-visual equipment together such as monitors, video playback decks, and game consoles.[EAI]

Scission

The process in which a chemical bond in a molecule is broken either by reaction with another molecule, such as water, or by the absorption of a high energy photon. [AMIA]

Scratching

Gouging of the magnetic layer or base as the tape passes through a machine. Videotape scratches will cause a loss of head to tape contact and appear as a solid line on the screen [BAVC]

Screen capture

An image or video that captures what is on a computer monitor or other visual output device. [EAI]

Screen saver

A computer program that overtakes the display screen if there are no keystrokes or mouse movements for a specified duration. [EAI]

SDTV (Standard Definition TV)

Refers to the TV systems commonly used around the world since the 1940s. [AMIA]

SECAM (Sequential Couleur Avec Memoir "sequential color with memory")

A color television standard with 625 lines per frame and 50 fields per second developed by France and the U.S.S.R. Color difference information is transmitted sequentially on alternate lines as an FM signal. One of three international standards, including NTSC and PAL. [BAVC]

Serpentine recording

A form of longitudinal recording where track one is written near one edge of the tape, and when the end of tape is reached, the head moves (or another head is used) and the recording proceeds in the opposite direction. When the tape returns to the starting point, the head moves inward one track (or another head is switched on) and the recording continues. This process is repeated until the last track (near the other edge) is reached. [AMIA]

Server

A computer program that provides services to other computer programs by responding to requests and supplying or accepting data. See storage. [Getty]

Shedding

A condition in which the oxide that forms the recording surface of a videotape has begun to separate from the base. Loose oxide may clog video heads causing a loss of picture. See also Sticky shed. [BAVC]

Signal

Analog video signal is an electrical signal that is continuously variable. Digital video signal is comprised of binary digits. [BAVC]

Signal to noise ratio (S/N)

Expressed in decibels (dBs), this term describes a ratio or difference of wanted audible or visual information (signal) versus unwanted information experienced by distorted sounds and pictures (noise). Comparatively high decibel numbers mean better sound or visual images. [BAVC]

Simulated color

Also known as "false color," or "colorized." Projected colors that are not the same as the original image. Some products use a single, colorized LCD, often with purple for dark shades and yellow for light shades (purple background/yellow foreground). Therefore, what should appear on a screen as blue may be yellow, green may be purple. [Projector People]

Sine wave

Type of pure waveform having an equal distance from its peak to the zero or center line and from its trough to the center line and in which the positive hump and negative hump of the wave are exactly equal in length, shape and height but flipped in a mirror image about the center line. [BAVC]

Single-channel video

The term "single-channel" refers to video or media work that involves a single information source (such as a DVD), a single playback device (such as a DVD player), and a single display mode (such as a flat-screen monitor). To cite a familiar example, when you play a DVD and view it on your television at home, you're showing a single-channel work. [EAI]

Skew

A bending of picture at top or bottom of television screen caused by the changing of the video track angles on the tape from the time of recording to the time of playback. This can occur as a result of poor tension regulation by the VCR or by ambient conditions which affect the tape. [Also known as flagging.] [BAVC]

SMPTE (Society of Motion Picture and Television Engineers)

Organization dedicated to researching, proposing, and promoting video standards. [BAVC]

SMPTE Time Code

Time code that conforms to SMPTE standards. It consists of an 8-digit number specifying hours: minutes: seconds: frames. Each number identifies one frame on a videotape. SMPTE time code may be of either the drop-frame or non-drop frame type. [BAVC]

Snow

1. White flashes appearing in the video image caused by random noise and/or loss of magnetic particles. 2. TV signal breakup caused by weak video reception. [BAVC]

Software

Computer programs held in the storage of a computer for some application. Program software performs the function of the program it implements, either by directly providing instructions (or "code") to the computer hardware or by serving as an input to another piece of software. [EAI]

Software art

A genre of digital art that emphasizes the creation of original or revelatory software applications - such as alternative Web browsing, image manipulation, or video-editing tools - rather than any single image or output produced with such a tool. Software art is typically compiled, but often freely distributed over the Web. [Variable Media]

Software-for-hardware

A type of emulation that simulates a program's native hardware environment on a machine that it was never intended to run on. For example, a program running the 2000 Windows operating system might emulate the microprocessor of a 1985 Amiga computer, enabling users to play a vintage video game such as Pong on a contemporary operating system. [Variable Media]

Source code

Program instructions in their original form. Programmers usually rely on another computer utility, such as a compiler or browser to translate source code into a form the computer can understand and execute. [Variable Media]

Stepping

Unsmooth packing, with transversally mispositioned sections. [BAVC]

Stereo

Sound received from two separate sources. Simulates human hearing.[BAVC]

Stress

Force per unit area, such as pounds per square inch (psi). A tape wound on a reel with high tension results in a tape pack with a high interwinding stress.[AMIA]

Subcarrier

The basic signal in all NTSC sync signals. It is a continous sine wave, usually generated and distributed at 2V in an amplitude, and having a frequency of 3.579545MHz. Subcarrier is usually divided down from a primary crystal running at 14.318180MHz, and that divided by 4 is 3.579545. All other synchronizing signals are directly divided down from the subcarrier. Color subcarrier is the 3.58 MHz signal that carries color information. This signal is superimposed on the luminance level. Amplitude of the color subcarrier represents saturation, and phase angle represents hue. [BAVC]

Submaster

High quality copy of a master tape used to make additional copies.[BAVC]

Switcher

Device for mixing multiple video signals. Used for special effects, transitions, generating titles. [BAVC]