G
A certificate issued by the MPAA indicating that a film is suitable for all ages. See also PG .

On the web: MPAA Ratings Explanation


Gaffer
AKA: Chief Lighting Technician
The head of the electrical department , responsible for the design and execution of the lighting plan for a production. Early films used mostly natural light, which stagehands controlled with large tent cloths using long poles called gaffs (stagehands were often beached sailors or longshoremen, and a gaff is a type of boom on a sailing ship). In 16th Century English, the term "gaffer" denoted a man who was the head of any organized group of laborers.

Ggain
Measures the light-reflecting ability of a projection screen. The higher the number, the greater the amount of light reflected back to the viewer.


Generator
AKA: Genny, Genny Operator
A mechanical engine which produces electricity from fuel (usually diesel). Frequently used for location shooting, either due to the unavailability or insufficient quantities of electricity locally available.

Geometric distortion
Unnatural bowing of straight lines or other distortion of shapes, especially at the sides and corners in a TV picture.

Geometric linearity
Ability of a television to reproduce lines, shapes, and sizes accurately.


Ghosting
Multiple overlaid TV images noticeable around the edges of objects; occurs when an antenna picks up the original TV signal along with duplicate signals reflected by tall buildings and other similar obstacles. DTV broadcasts can suffer from ghosting, which is sometimes called multipath.


Giraffe
A mechanically extendable and manipulated boom microphone .

Go Motion
AKA: Go-Motion
A form of animation similar to stop motion , but which incorporates motion blur . Ordinary stop motion cannot produce motion blur as motion only occurs between frames. Robotic models that are moved during the exposure of each frame produce motion blur , and thus are more realistic. Pioneered by Industrial Light and Magic for Dragonslayer .

Ggrayscale
Range of gray at different intensities from completely black to completely white. Since color information is overlaid atop black-and-white information in a composite , S-Video , and component -video signal, the ideal is to set the entire range of the grayscale as close to the standard of 6,500K as possible to preserve color fidelity.

Grayscale Variation
Geek box term . The average variation above or below 6,500K, measured on the grayscale from 20 to 100 IRE in 10-IRE increments.


Greenscreen
A newer technique similar to bluescreen , however utilizing a key green background. Research showed that substantially better results could be gained by filming on green instead of blue, as effects stock was more sensitive to separating key green from other (foreground) colors. See also chromakeying .

Greensman
A member of the crew who procures, places, and maintains any vegetation on a set .

Grindhouse
A term used to describe movie theaters common in the U.S. from the 1950s onward, that specialized in showing, or "grinding out" as many B movies as they could fit into their schedules. The term is also used to describe the type of B movies -- commonly violent, exploitative, or just plain racy -- that were shown in such theaters.

Grip
In the USA, a grip is a skilled person responsible for the set up, adjustment and maintenance of production equipment on the set . Their typical duties involve camera movement, lighting refinement, and mechanical rigging. In the UK, grips work exclusively with equipment that the camera is mounted on. Contrast with swing gang , see also key grip .