Glossary -L-
LANC — Local Application Network Control, a Sony-developed system for controlling VCRs (mostly 8mm Hi8 camcorders) over a two-way communications link.
Lasso — Adobe paint tool for selecting parts of a picture.
Layer — Part of a computer image, separate from the other parts, which can be changed independently from them, like changing the background behind a cartoon figure.
LCD panel or computer display panel — LCD device which when placed on an overhead projector can project computer data.
LCD projector — Projector (with built in light source as opposed to the LCD panel that used an overhead projector for light) using a liquid crystal mosaic to create the image.
LCD viewfinder — Liquid Crystal Display, a color TV monitor made of a flat panel rather than a CRT. Usually folds out from a camcorder or is imbedded in it.
Lead-acid or Gel-cell — Battery designed like a miniature car battery, only with gelatin inside rather than liquid. Less expensive than NiCd; used in camcorders.
Leader — Unrecorded space (from 10 seconds to 3 minutes) at the beginning of a tape, often used to protect the actual program from threading damage. Also unrecordable plastic tape attached to the beginnings of cassette rolls.
Leaf shutter — A flap inside a photographic camera that moves aside for a moment to let light enter and then snaps closed.
LED — Light emitting diode, a tiny lamp that can blink very quickly, uses little power, and lasts a long time. Often used as an indicator on equipment.
Legal colors — Colors that reproduce correctly in NTSC video. Some computer generated colors are called “illegal” in that they are out of the range of what common TVs can display.
Legal video — Video production, editing, and display as it relates to the law and the courtroom.
Lens format — Describes the size of the lens’s focused image. It should match the size of the camera’s pickup chip.
Lens shade — A funnel-shaped visor that attaches to the outside of a lens shading it from lights and the sun.
Lenticular — Gray, metallic-looking projection screen with tiny vertical grooves (looks like smooth corduroy) to distribute most reflected light straight back and to the sides (where the audience sits) and reflects very little on the ceiling and floor.
Level 1 videodisc player — Often a consumer model player with features such as freeze frame, picture stop, chapter stop, scan, and two-channel audio but without the computer memory or the ability to select on its own which sequences to show.
Level 1/2/3 videodisc player — A combination level 1, level 2, level 3 videodisc player.
Level 2 videodisc player — An educational/industrial videodisc player, usually with all the level 1 capabilities plus a small computer built in. Computer programs (instructions) coded in the audio track of the disc are loaded into this computer when you start the disc playing, telling the player which sequences to play as a result of viewer responses.
Level 3 videodisc player — Videodisc player linked to an external computer. The computer program, perhaps from a floppy diskette, controls the sequences the videodisc player will play. The computer may also display graphics and questions of its own. The disc serves mostly as a storehouse of still and moving pictures and sound.
Level 4 videodisc player — Videodisc player with computer, able to read a large computer program from the disc, and thereafter runs like a level 3 player.
Light meter — Electronic device that measures the brightness of a light (incident light) or the brightness of a scene (reflected light) and gives a readout in footcandles or lux.
Light pen — Pen-shaped device connected to a computer that the viewer points or touches to a TV screen in response to computer questions rather than typing the answers on the computer’s keyboard.
Light valve projector — Expensive, professional projector that creates bright images by bouncing light off a reflective surface inside. The reflective surface changes its reflectivity based on video or computer images presented to it.
Lighting grid — Framework of pipes connected to the studio ceiling from which lights are hung.
Lighting plot — A drawing to show where the lights are to be aimed. May also include fixture numbers and circuit numbers and show prop and performer positions.
Lighting ratio — A comparison between the brightest part of a subject and the darkest. If the brightest white in a performer’s shirt measured 60 fc (footcandles) and his black hair measured 2 fc, then the lighting ratio would be 60 2 = 30.
Lightning arrester — Device which clips onto an antenna or cable TV cables, and connects to a grounded wire. It is designed to divert the shock of a lightning bolt so that the current doesn’t damage your equipment.
Limiter — Electronic audio device that automatically reduces the volume of loud audio signals but doesn’t change the normal or weak signals.
Line — An external auxiliary input often used for a video signal. Can also be the final video or audio output signal from a device.
Line doubler — Device that doubles the scan lines that makes a picture, essentially placing lines between lines, improving the look of video when shown on computer-like devices such as computer projectors.
Line or program monitor — TV monitor that shows the final signal being broadcast or sent to the VTRs.
Line quadrupler — Device that quadruples the scan lines in a picture, making video look better when shown on high resolution computer projectors.
Linear (or normal) audio track — Audio recording made in a line along the edge of a video tape (as opposed to hi fi sound imbedded in the video tracks on the tape).
Linear audio track — A stripe of magnetic vibrations along the edge of a video tape that contains the audio signal, laid down by a stationary record/play head.
Linear key — Key effect where the amount of a color (or brightness) determines how much of another camera’s image will be visible, creating a natural-looking key effect.
Linear screw rod — Inexpensive satellite aiming actuator moved by a long threaded bar.
Lip Sync — Synchronization between the performers’ audible words and the movement of their lips.
Liquid crystal light valve (LCLV) projector — Expensive, professional projector that uses amorphous (not dots of) LCD material to sense a dim CRT image and make a surface reflective. Light from a bright projection lamp reflects off the surface to make the projected image.
Lithium ion — Ultra small battery for camcorders.
LNA — Low Noise Amplifier used to boost the dish antenna’s signal. Satellite signals are so weak they have to be amplified (multiplied) 100,000 times. Special circuits with premium grade transistors are needed to allow the signal to be amplified so much without adding appreciable visual “noise” to the signal.
LNB or LNC — Low Noise Blockconverter or Low Noise Converter, an LNA with a circuit built-in that lowers the microwave frequencies, making them pass easily through common coax wire to your satellite receiver.
Lo Z — In audio, any input of 500 ohms impedance or less.
Logo — Symbol or trademark representing a specific company, or organization, or TV station.
Loop antenna — Circular portable UHF antenna.
Loop or bridge — An electrical connection which allows most of the signal to enter one socket and continue out an adjacent socket to be used elsewhere.
Loop through — The act of sending a signal to and through a device (using a bridged input) and then on to another device.
Lossy — Compression method that discards data and degrades the image quality. High degrees of compression are possible.
Lossy — Compression method that discards some data, to some degree damaging the signal it represents.
Low contrast filter — Lens filter that reduces contrast by making shadows lighter.
Low cut filter — An audio circuit, often built into mixers and mikes, that reduces low tones from a sound signal.
Low level or microphone level — Weak audio signal, as from a microphone.
Low light level camera — TV camera designed to “see” with very little light—used in military and surveillance.
Low-pass filter — Filter placed between a radio transmitter and its antenna to reduce the harmonics from being broadcast. The harmonics interfere with people’s TV reception.
LP — Long play—The 4-hour speed of a VHS VCR.
LPTV — Low-Power Television-the technique of broadcasting local programming through a very low-power, inexpensive VHF TV transmitter. Limited signal range keeps LPTV stations from interfering with distant TV stations using the same channel frequency.
LTC or Linear Time Code — Time code recorded in a linear stripe along the tape, perhaps on a longitudinal audio track.
Lumen — A measurement of a source’s light brightness. Lumens per square foot equals foot-candles.
Luminance — The black-and-white (brightness only) part of a video signal.
Lux — A measure of illumination, the amount of light needed to make a 1-volt video signal.
Lux — A measure of the brightness of an object in a scene. Cameras need a certain degree of scene brightness in order to register a picture. 10 lux equals about 1 footcandle, another measure of brightness.
LV — Laservision. A videodisc read by a laser, the light of which reflects off microscopic pits in the disc. Not the same as CED videodiscs. which use a groove.
