Chroma: In the video industry, a measure of color intensity it describes the saturation of a hue.

Cine: Of or relating to the film and video industries.

Circuit Breaker: An automatically operated electrical OFF switch designed to protect an electrical circuit from damage caused by overload or short circuit. A circuit breaker can be reset once it switches off and stops electrical flow.

Color Balance: An arrangement of hue, chroma and value within a design that produces a sense of equilibrium, i.e., no single colored area commands attention to the detriment of the entire arrangement.

Color Correction: Adjusting the color temperatures of various light sources so that they are all the same, or to make them match existing light sources, e.g., sunlight or fluorescent light. This is usually accomplished by utilizing color media (filters), but adjusting the input voltage levels is a method sometimes used for certain light sources.

Color Frame: An apparatus used to hold color media or other types of filters. It can be of various shapes and sizes and may be composed of one or more pieces.

Color Temperature: A linear scale for measuring the color of ambient light with warm (yellow) light measured in lower numbers and cool (blue) light measured in higher numbers. Measured in terms of degrees Kelvin,daylight is approximately 5600-degrees Kelvin, a candle is approximately 800 degrees, an incandescent lamp is approximately 2800 degrees, a photoflood lamp is 3200 to 3400 degrees, and a midday blue sky approaches 10,000-degrees Kelvin. *Named for engineer and physicist Lord Kelvin (William Thomson), who conceived of the thermodynamic temperature scale, in 1848.

Color Wheel: An apparatus holding several different gels that can be rotated by hand or motor such that any one gel can be placed in front of a light source with relative ease.

Conductor: Generally, anything that will carry electrical current, but usually refers to an insulated wire.

Connector: Specifically, the name for a family of electrical wiring devices, such as plugs and receptacles, composed of one or more contacts a means for electrically attaching a conductor to each contact a means for electrically insulating each contact from the other an overall insulating material around the complete assembly, such that only the contacts are exposed when the connector is properly installed to the item containing the conductors. Any item used to make an electrical connection between two or more separate conductors.

Contrast Ratio: Compare two reflected-light readings: The lightest significant area of the subject or scene, versus the darkest. Each medium or method of reproduction has different brightness ratio limits. Projected films about 125:1 (seven stops) Video about 32:1 (five stops). See Lighting Ratio.

Convection Cooling: A cooling process whereby air circulation is maintained in order to transfer heat from an object to the atmosphere around it by supplying adequate ventilation or heat sinks without the use of electrical or mechanical items such as fans, blowers, etc.

Convex: A term used to describe a lens side that is outwardly and usually spherically curved.

Cookie (Cooky): Short for Cucalorus.

Cool Light: Light having a color temperature of approximately 3600°K to 4900°K, i.e., bright-white to blue-white.

Crank-Up Stand: A stand that is raised and lowered with the aid of a rotating handle and gear mechanism.

China Silk: A fabric used for linear diffusion material it spreads the light linearly.

Chroma: In the video industry, a measure of color intensity it describes the saturation of a hue.

Cine: Of or relating to the film and video industries.

Circuit Breaker: An automatically operated electrical OFF switch designed to protect an electrical circuit from damage caused by overload or short circuit. A circuit breaker can be reset once it switches off and stops electrical flow.

Color Balance: An arrangement of hue, chroma and value within a design that produces a sense of equilibrium, i.e., no single colored area commands attention to the detriment of the entire arrangement.

Color Correction: Adjusting the color temperatures of various light sources so that they are all the same, or to make them match existing light sources, e.g., sunlight or fluorescent light. This is usually accomplished by utilizing color media (filters), but adjusting the input voltage levels is a method sometimes used for certain light sources.

Color Frame: An apparatus used to hold color media or other types of filters. It can be of various shapes and sizes and may be composed of one or more pieces.

Color Temperature: A linear scale for measuring the color of ambient light with warm (yellow) light measured in lower numbers and cool (blue) light measured in higher numbers. Measured in terms of degrees Kelvin,daylight is approximately 5600-degrees Kelvin, a candle is approximately 800 degrees, an incandescent lamp is approximately 2800 degrees, a photoflood lamp is 3200 to 3400 degrees, and a midday blue sky approaches 10,000-degrees Kelvin. *Named for engineer and physicist Lord Kelvin (William Thomson), who conceived of the thermodynamic temperature scale, in 1848.

Color Wheel: An apparatus holding several different gels that can be rotated by hand or motor such that any one gel can be placed in front of a light source with relative ease.

Conductor: Generally, anything that will carry electrical current, but usually refers to an insulated wire.

Connector: Specifically, the name for a family of electrical wiring devices, such as plugs and receptacles, composed of one or more contacts a means for electrically attaching a conductor to each contact a means for electrically insulating each contact from the other an overall insulating material around the complete assembly, such that only the contacts are exposed when the connector is properly installed to the item containing the conductors. Any item used to make an electrical connection between two or more separate conductors.

Contrast Ratio: Compare two reflected-light readings: The lightest significant area of the subject or scene, versus the darkest. Each medium or method of reproduction has different brightness ratio limits. Projected films about 125:1 (seven stops) Video about 32:1 (five stops). See Lighting Ratio.

Convection Cooling: A cooling process whereby air circulation is maintained in order to transfer heat from an object to the atmosphere around it by supplying adequate ventilation or heat sinks without the use of electrical or mechanical items such as fans, blowers, etc.

Convex: A term used to describe a lens side that is outwardly and usually spherically curved.

Cookie (Cooky): Short for Cucalorus.

Cool Light: Light having a color temperature of approximately 3600°K to 4900°K, i.e., bright-white to blue-white.

Crank-Up Stand: A stand that is raised and lowered with the aid of a rotating handle and gear mechanism.

Crown Glass: A type of glass that has excellent optical quality, used for lenses and mirrors.

C-Stand: Short for Century Stand.

Cucalorus: An opaque or translucent material having one or more cut outs that will allow light to pass through in order to project a dappled form or pattern, such as the suggestion of the shadows of tree branches, on the subject and background.

Current: Short for Electrical Current.

Cutter: A narrow, rectangular flag, ranging from 18" to 72" in length, and 6" to 24" in width, generally used to block only a portion of the light beam.

Cyc: Short for Cyclorama.

Cyc Light: Short for Cyclorama Light.

Cyclorama (Cyc): A vertical surface, which is used to form the background for a theatrical set that, is usually made of heavy cloth drawn tight to achieve a smooth, flat surface, or left loose and textured. It is meant to suggest limitless visual space. Traditionally, cycloramas were dome shaped or horizontally curved, but may now also be flat or vertically curved, as well.

Cyclorama Light (Cyc Light): A light source mounted at the top or bottom of a cyclorama in order to light it in a smooth, uniform manner.

Daisy Chain: A control signal wiring system employed in the interconnection of a plurality of some electronic items, such that the first item`s output connector is connected to a second item`s input connector via a control cable. A third item is connected to the second in the same manner, and so on until all items have been connected. The control console is connected to the input connector of the first item only, but sends data to all items via the interconnecting control cables. Some items that can sometimes be daisy chained are color scrollers, automated light sources and dimmer racks or packs. See Feed Through.

Daylight: Light that has a color temperature of approximately 5500- 5600°K, which has been approximated to be the color temperature of ordinary sunlight at midday under normal atmospheric conditions.

Daylight Filter: A filter used to balance light from a warmer source, so that the spectral distribution will approximate daylight, i.e., 5500-5600°K.

DC: Abbreviation for Direct Current.

DC Voltage: Short for Direct Current Voltage.

Dichroic: A type of metallic coating applied to glass and some other materials that allow certain wavelengths of light, or other electromagnetic radiation, to pass, while reflecting all others.

Diffuse: To scatter light using diffusion material. A term used to describe a somewhat dull or stippled surface that is moderately reflective.

Diffuse Light: Soft, generally even illumination.

Diffuser: Generally, something made of diffusion material that softens the quality of the light passing through it to produce a more flattering light with less noticeable shadows. In the film and video industries, a fabric panel, used for diffusing, with the light source being a light source or sunlight. They are available in a variety of sizes, shapes and materials of varying textures and opacities.

Diffusion: Short for Diffusion Material or Diffusion Media.

Diffusion Frame: An apparatus used to hold diffusion material. It can be configured of various shapes and sizes, and may be composed of one or more pieces.

Diffusion Material: Any reflecting or transmitting media, for which the reflected or transmitted light is distributed uniformly, i.e., scattered over a wide range.

Diffusion Media: See Diffusion Material.

Digital: A term used to describe the use of binary code to record information that has been reduced to numerical form usually instructional information in regard to control consoles.

Digital Multiplex (DMX): A system that simultaneously transmits more than one digital signal.

Dim: To change the intensity of a light source.

Dimmer: An apparatus used to control the intensity of a light source.

Dimmer Pack: A portable housing that contains a group of electronic dimmers, usually not less than four nor more than 24. Some dimmer packs are designed for permanent installation.

Dimmer Panel: An apparatus, usually 19" long, that contains a group of electronic dimmers that are installed into a dimmer rack.

Diode: A solid-state rectifier.

Direct Current (DC): An electrical current that maintains constant direction. Batteries provide DC current.

Direct Current Voltage: A voltage that maintains constant polarity.

Direct Lighting: Illumination on a subject or area that goes directly from the front of the light source in a straight line to the subject or area.

Distribution: Short for Light Distribution.

DMX: Abbreviation for Digital Multiplex.

DMX 512: A somewhat unique digital multiplex signal with specific characteristics that is commonly used in the stage and studio lighting industries. Control consoles designed to generate this signal were originally designed to control a maximum of 512 apparatuses, usually dimmers, but now can control many more.

Donut: A flat metal apparatus with a circular hole in the center used to reduce halation and sharpen the image when using patterns.

Dot: A small, round scrim, diffuser, reflector, or gobo, placed close to a light source, used for dimming, softening, bounce lighting or casting shadows, respectively. They are usually 3" to 10" in diameter.

Double-Ended Lamp: A somewhat elongated lamp that has a base and contact on each end.

Duvetyn (Duvatyne, Duvetine, Duvetyne, Duvyteen): A smooth,lustrous, velvety opaque fabric used for butterflies, cutters, flags, gobos and overheads in the film and video industries.