The time between a device being requested to do something and the start of the device actually doing it. It’s a measurement usually used for LCDs where the shorter the latency the better. NSTC requires a latency of no more than 16ms in order to update the screen in time without leaving a ghost of the previous image.

Liquid Crystal Display. A display device for generating color images using a matrix of LCD pixel elements. Each pixel element consists of 3 sub-pixels and an RGB color filter of red (R), green (G), and blue (B). By controlling the voltage to each sub-pixel of an LCD, each cluster of RGB pixels can create a full spectrum of colored light. LCDs are used in flatscreen displays, cameras and notebook computers to name a few. Nearly every projector made with LCD technology uses 3 separate LCDs, one each for red, green and blue. Light from the projector lamp is separated into RGB with a set of dichroic mirrors. The three light beams (RGB) are passed through separate LCDs and recombined to project a color image.

Liquid Crystal on Silicon. Type of LCD panel that reflects light as opposed to blocking it. Usually offers a comparatively high fill rate creating a smooth image but generally has difficulty giving a high contrast ratio.

Light Emitting Diode. A light generating technology that uses a semiconductor diode that emits monochromatic (single color) light when charged. LEDs are used in remote controls that are used to control electronic devices such as large displays. They are also used in pocket projectors as a light source, large outdoor electonic displays, and as indicators on electoronic devices such as power supplies and cameras.

The Lens Shift feature of a projector allows the optical lens to be physically shifted up and down (vertical) and/or left and right (horizontal). Some lens shift mechanisms are motorized with vertical lens shift being the most popular. Lens shift will can avoid or minimize the need for keystone correction. It is also used to geometrically align images when stacking projectors.Â

A method of preserving the originally aspect ratio of a production when presented on a projector with a different aspect ratio. This is accomplished by showing the full image and black where no image exists.

Low Frequency Effects. The .1 channel in 5.1, 6.1 or 7.1 sound. Used for effects and is limited to 120 Hz.

A projector that uses an imaging system that either blocks or reflects light such as LCD, LCoS or DLP.

Component device that duplicates scan lines to create a full frame from a field and then updates the screen completely every 60th of a second. Reduces flicker and the appearance of scan lines making an image look smoother.

A low-voltage pre-amplified signal usually between .3 and 5 volts.

A display’s ability to show an image’s geometric characteristics accurately. Also called geometric linearity.Â

Low-Noise Block converter. The LNB sits at the end of a pole facing the dish of a satellite dish assembly. It converts the incoming signal to a lower set of frequencies to make them easier to send over a wire without distortion. The lower the rated degrees of an LNB, the cleaner the picture will be.

A long throw lens allows greater distance between the projector and the screen while being able to maintain the image size and brightness of a shorter throw lens for any given projector. Depending on the room, a long throw lens may be required due to mounting constraints nearer the projected image.

A filter that only passes frequencies under a specified Hertz.

A measurement unit of total illumination. Typically a 100-watt light bulb outputs 1700 lumens over a wide area. Projector light output is measured in ANSI lumens. A projector with a higher lumen number will produce a brighter image for a given image size. See ANSI Lumens

The black and white part of a video signal. It is signified by the letter Y. Signals with a separated luminance and color signal avoid interference. This interference can result in dot crawl among other image artifacts.

A standard for measuring light equal to the amount of visible light per square meter incident on a surface. 1 lux = 1 lumen/square meter or 0.093 foot-candles.