Glossary » L

Local Area Network - a way of linking computers together over long distances. Today Ethernet is the most common way of doing this, although there are other standards such as Token Ring. Ethernet comes in speeds of 10Mbit (Megabit – divide by eight to get Megabyte), 100Mbit and 1000Mbit (Gigabit) although 10 Gigabit is starting to appear. There are also wireless versions which are referred to as 802.11b (11Mbit), 802.11a (54Mbit) and 802.11g (54Mbit) the difference here being 802.11b/g uses a 2.4GHz frequency and 802.11a uses a 5GHz frequency. The common name for all three standards is WiFi.

A page or screen orientation that is wider than it is tall.

Liquid Crystal Display. A non-emissive display that uses liquid crystals to control the amount of light that escapes from a fluorescent backlight. Using the twisted-nematic principle, the liquid crystals are sandwiched and twisted through 90 degrees by way of two substrates that have been rubbed at 90 degrees to one another. There are also two opposing polarising layers above and below the substrates that would otherwise block the light, but because the twisted liquid crystal layer can ‘untwist’ this polarised light, a gateway is effectively opened for light to escape. However, by applying differing amounts of voltage, you can variably reduce the amount of twist, and consequently the amount of light that is transmitted. In order to produce a colour picture, each pixel consists of three sub-pixels fitted with red, green and blue filters. See passive matrix, active matrix, and liquid crystal.

A light map is best thought of as a snapshot of the lighting details of a scene but with all other scene details removed. In simple terms it’s a graphical representation of light quality, direction, distance and so on recorded as a simple texture, a kind of static light blueprint if you like.

Used to describe analogue tape-based systems where the project is built up in sequence. Doesn’t allow for insertion or adjustment of earlier sequences without restarting the edit.

The compound found in LCDs. These compounds exist in a liquid-crystal state, and have two main properties. First, an electrical field can influence the semi-crystalline structure, and secondly, in certain orientations, the crystals can affect the transmission of light. Combining the two allows one to predictably control light emission, thus making these compounds ideal for LCD pixels.

The process of searching, selecting and marking of original source material which is to be used in the video project.

Type of compression which does not lose information, although at the cost of much higher file sizes than those using lossy compression.

Type of digital compression which permanently throws away information to achieve low file sizes. Employed by popular JPEG format in varying degrees.

Similar to chroma keying, but removes areas of a certain brightness in the original video rather than colour.

Also called Luma value. The light value of a picture element. Combined with chrominance to create the end image.