Video & Film Glossary
aperture = the open area of the iris, the variable opening behind the lens that controls the amount of light admitted to the camera.
aperture = the open area of the iris, the variable opening behind the lens that controls the amount of light admitted to the camera.
ambient light = the general light surrounding the subject, filling in the shadows, generally of a soft, low- contrast quality and often from sources of light reflecting off objects in the space.
arc light = a powerful lamp in which the electric current flows between two electrodes. A carbon arc operates in the normal atmospheric pressure, while a mercury arc works with the current flowing through an enclosed mercury vapor. This pressure can sometimes be very high.
accent light = an instrument that focuses attention on an area. It can be in any position: key, kicker, or back.
backlight = an instrument positioned directly behind and above the subject, aimed at the subject’s back. Care must be taken not to have the backlight shine into the lens of the camera, creating flares.
bail = also known as the yoke, the bail is a U-shaped bracket that holds an instrument, either hanging from a pipe clamp or on a stand connector.
ballast = a device required to operate any discharge light, such as arc lamps (both simple arcs and HMIs) and fluorescent, designed to limit amperage to a specific level.
barndoors = hinged black metal flaps that attach to the front of a lighting instrument to limit and shape the pattern of light.
beadboard = a type of housing insulation made of polystyrene beads formed into a flat board. It is used to bounce soft, diffuse light.
beam angle = the diameter of the beam angle is defined as the area of the light field that is 50% or more of the peak intensity of the beam.
blackwrap = a thick, durable, aluminum foil that has been anodized flat black used on hot lights to control spill and to shape the beam.
blondie = a 2000W quartz open-face light, the big sibling of the Redhead.
blackbody radiator = a theoretical incandescent source used in defining the concept of color temperature. The spectral power and color distribution of a blackbody source depend only on temperature.
brightness = ability of a surface to reflect or emit light in the direction of the viewer.
C-clamp = a large C-shaped clamp with a baby stud or junior receptacle welded to it that is used to mount lights to beams.
C-stand = a special, highly adaptable lighting stand, short for Century Stand. The special dual plate head can mount a boom arm or a light mount, can clamp flat material on or can be used for setting flags and nets.
chicken coop = an overhead suspended light box that provides general downward ambient or shadowless fill light.
chroma key = a method of separating a subject against a background of a solid primary color (usually green or blue) for the purpose of compositing that subject against a new background.
color conversion gel = a gel used to convert a light source from one color temperature to another.
color correction gel = a gel that adds or subtracts green to a light source.
color temperature = a system of evaluating the color of a light source that has a continuous color spectrum by comparing it to a theoretically perfect temperature radiator called a black body. The temperature is measured on Kelvin scale.
contrast = the ratio between the lightest area of the scene (or picture) and the darkest area of a scene (or picture). Lighting contrast refers to the light intensity differences between the sources.
cookie = also called cucaloris. An irregularly perforated shadow-forming flag, opaque or translucent, made of plywood or plastic, for example.
CRI = color rendering index. This is measure of the spectrum content of the light source and, thus, its ability to render colors accurately.
CRT = cathode ray tube.
cutter = a long black flag that is used to “cut “light from an area of the set.
cyclorama (cyc) = stage background, usually white with rounded corners, that is used to create a limbo or sky effect. Made of plaster or starched plastic. Sometimes painted green or blue for shooting foreground elements to be composited using a chroma key process.
cyc strip = lighting instrument shaped like a trough with up to twelve bulbs for even illumination of a cyclorama.
daylight = light commonly considered to have a color temperature of 5500 K to 6000 K.
diffusion = material used in front of lighting fixtures to soften the light they produce.
diffused light = light originating from a physically large source. It is either reflected (bounced) off a surface or directed through a diffusing medium.
dimmer = an instrument used to change the voltage of lights on the set, regulating in this way their intensity. Color temperature of the lights will lower when dimmed.
discontinuous spectrum = characteristic of light sources, such as fluorescent tubes, which emit energy only in a few wavelength bands of the spectrum. Some colors are not represented in the discontinuous spectrum.
DMX = short for digital multiplexing, DMX is a digital standard for lighting control set by USITT.
dolly = a wheeled vehicle for mounting a camera and accommodating a camera operator and assistant. Often equipped with a boom on which the camera is mounted.
egg crate = a deep grate that allows soft light to be controlled into a directional beam rather than spreading all over the place. The deeper the egg crate is, the more control it provides.
electronic ballast = a solid state ballast. The term electronic ballast is synonymous with flicker-free square-wave ballast (HMI) or high frequency (fluorescent).
expendables = supplies that are used up in production, such as gaffer tape, gels, black wraps.
exposure = a process of subjecting a photographic film to any light intensity for a given time, resulting in a latent image.
eye light = a small instrument positioned to create a glint in the subject’s eye.
fill light = soft light used to reduce the darkness of the shadow areas.
flag = an opaque rectangle, usually black cloth stretched over a wire frame, that is used to block light to a certain area. Same as a gobo or cutter. These are sometimes made out of thin plywood painted black.
flicker-free = an HMI or fluorescent ballast that provides a square-wave or high frequency signal that eliminates light-level pulsation when filmed at any shutter speed.
flood = the spread of the beam of a fixture that is broad and relatively weak.
fluorescent = a tubular lamp that creates light by exciting mercury vapor gas, which then emits ultraviolet (UV) radiation.
foamcore = a white, glossy card material reinforced with ¼-in. styrofoam and used to bounce light.
focal length = the distance between the optical center of the lens and the target when the lens is focused on infinity.
frequency = the number of cycles per second on alternating current, measure in hertz.
Fresnel = a type of lens that has the same optical effect as a standard plano-convex lens but has reduced weight and heat retention. A light fixture that uses Fresnel lens.
F-stop = a number obtained by dividing the focal length of the lens by its effective aperture. F-stop numbers represent the speed of the lens at any given diaphragm setting.
gaffer = the head of the lighting crew. The gaffer works directly under the director of photography.
gaffer tape = heavy, fabric –based tape that rips cleanly in the direction of the wave. It is used for securing cables and lights on the set.
gamma = a graph line that describes a film emulsion’s reaction to tonal gradation and its innate contrast. Also called D log E curve or characteristic curve.
gel = a transparent, colored plastic sheet – usually polyethylene – used to change the color of light. In early theater the sheets were made of colored gelatin.
glow light = a weak light source that creates a bit of a glow on the actor’s face.
gobo = a large flag, cutter, or even a full sized flat used to cast a shadow on part of the set. The name comes from the early film days, when the director would call, “go black out” a portion of set. This was abbreviated on the production notes as “GO B.O.” then just gobo.
green screen = a pure green, evenly lit background. The process where all green background is rendered transparent, so that a new background can be placed behind the subject.
grid = pipe system above soundstage where lights re hung.
Griffolyn = a polyethylene laminate with a stranded reinforcement. It’s popular as a large reflector or flag material for frames.
grip = a crew member responsible for the nonelectrical aspects of lighting and rigging and for the camera dolly and other camera platforms.
hair light = a backlight positioned above and just slightly behind a subject to create highlights on the hair.
halogen = elements such as iodine, chlorine, bromine, fluorine, and astatine are classified as halogens. They are used in manufacturing tungsten halogen lamps, such as quartz-iodine bulbs.
Hertz = a measure of frequency in cycles per second (Hz).
high key = a bright lighting style with low contrast and bright highlights.
HMI = a metal halide discharge lamp constituting, in effect, a mercury arc enclosed in a glass envelope. Short for hydrargyrum medium arc-length iodide. Gives off color temperature equivalent to daylight.
hot spot = a very bright area in the scene, caused by excessive light or a strong reflection.
housing = the metal casing that surrounds the bulb and reflector of a lighting fixture.
incandescent = any type of electric light that creates light by making a metallic filament (usually tungsten for film lights) glow by applying current to it.
Kelvin scale = a temperature scale used in expressing the color temperature
key light = the main source used to light a subject. Its direction and amount relative to fill light establishes the mood of the illumination.
kicker = a light positioned behind the subject and off to the side opposite the key.
lamp = a term basically used for the light bulbs of various design, but also employed to describe the lighting instrument as a whole.
louvers = thin, parallel strips with a black finish arranged in a grid pattern that is placed in front of a soft light source. Louvers reduce spill light and direct the light in one direction.
low key = lighting style in which the majority of a frame is composed of dark areas. Usually enhanced by dark costumes and sets. High key-to-fill lighting ratio is employed for this effect.
lumen = the light emitted by a source of power of one candela that falls on one square unit of surface at one unit of distance from the source.
luminaire = a European term for lighting instrument, used more in the theatre than in television or film.
lux = an international unit of light intensity used primarily in Europe. One lux equals one lumen per
mafer clamp = an all-purpose grip clamp (cam screw tightening) that can receive a number of different mounting attachments, such as a baby stud or flex arm.
mountain leg = the leg of a three-leg stand that extends to allow the stand to remain upright on uneven ground.
net = a bobbinet or black net fabric on a frame, used to reduce light intensity and is available in single (half stop) or double (full-stop)
nook light = a small, lightweight open-face fixture that typically uses a double-ended bulb and a V-shape reflector.
open-face light = a fixture that has no lens to focuse light, only a bulb mounted in front of a reflector.
PAR = a lamp that incorporates bulb, reflector, and lens into a single unit. Short for parabolic aluminized reflector. Auto headlights are PAR globes.
quartz bulb = a tungsten-halogen globe. The term comes from the heat-resistant quartz glass used in this bulbs.
redhead = an open-faced lighting fixture, sibling of the Blondie.
reflector = any shinny surface used to bounce light – often a foil-covered board. Collapsible fabric reflectors are very handy for location shots.
rigging = positioning lamps in the studio according to the preliminary lighting plot.
rim = a backlight that makes a rim around the head and shoulders of the subject from the perspective of the camera.
sandbag = a sand-filled bag used to stabilize stands and equipment by adding deadweight or counterweight.
scoop = a studio lamp of a soft, wide, round pattern.
scrim = a circle of wire mesh, which slides into the ears in front of a fixture and reduces the intensity of the light, without changing the color temperature.
shutters = venetian blind-like metal slats that are mounted on a fixture in place of barn doors for use as a douser.
silk = silk fabric used to soften and cut the intensity of light. It is used in all sizes.z
Sky pan = a large, soft light fixture used for general fill, is a nonfocusable studio lamp, providing illumination over a broad area, such as set backdrops.
snoot = a black metal cylinder or cone mounted on the ears of a fixture to narrow the beam.
soft box = a cloth and wire umbrella-like contraption that holds a large sheet of diffusion material in front of an instrument.
soft light = a type of open-faced light in which the globe (usually a quartz tube) is hidden in the base and bounced outward off a curved white reflector. No direct light is used. The large aperture and reflected light creates light with soft shadows that is often used as a fill light.
space light = a large silked cylinder that hangs above the set to create soft ambient illumination.
spill = the light that squirts where you don’t want it.square wave = a type of AC created by an electronic ballast that renders HMI lights flicker free.
spot = a beam focused into a narrow, relatively strong beam of light.
talent = on-camera people or animals, usually actors, not necessarily talented ones.
tilt = the vertical rotation of a camera on tripod.
top light = a light that shines directly down on the subject.
tungsten light = light generated by an incandescent lamp with a tungsten filament.
volt = a measure of electrical energy (V), describing the electrical potential, or difference between positive and negative.
watt = a measure of power (W).
wrap = the process of taking down lights and coiling table cable that begins after the last shot of the day has been completed successfully.