Safety Cable: A steel cable that has a clip on one end and a loop on the other. It is intended to be threaded through a piece of hanging equipment and around a support structure, such as a batten or truss, and then clipped to its loop. It then acts as a safety support should the primary support, such as a pipe clamp or hanging arm, fail.

Safety Screen: A metal wire screen, placed at the front of an open-face light source, designed to retain large pieces of broken glass should the lamp break.

Sail: The total surface area of an overhead, butterfly, scrim, flag or cutter.

Saturation: The aspect of color that determines the difference from white at a constant hue, i.e., the property of any color that distinguishes it from a gray of the same brightness. High saturation is one with little or no white light added to the color, like deep red. Low saturation is one with a large amount of white light added to the color, such as light pink.

Scoop: Named for its scoop-like shape, an open face flood light with a large, diffuse reflector that is essentially the body of the light source. The reflector is parabolic, spherical, or ellipsoidal and is generally made from unpainted aluminum.

Screw Base: A threaded, cylindrical shaped lamp base with a single contact on the bottom. The threaded part of the base holds the lamp into its socket and acts as the second contact.

Scrim: In the theatre industry, a thin, gauze-like curtain. When illuminated from the front, it appears opaque, and when illumination is present behind it but not on it, the scrim becomes almost transparent. It can also appear translucent when there is some illumination directly on it, and some illumination present behind it, in the proper proportions. In the film and video industries, a fabric panel, used for dimming, with the light source being a lamp head or sunlight. They are available in variety of sizes and shapes and materials of varying density. In the film and video industries, a round, framed metal screen, available in various densities, placed on the front of a light source to act as a dimmer. They are also available so that only half of the frame is screened, therefore allowing for only a portion of the light to be dimmed. For us, a metal screen used in front of a light to reduce intensity without diffusion.

Scrim Set: A set of metal scrims comprising a full double density, half double density, full single density and half single density.

Sealed Beam Lamp: A lamp with an integral light source, reflector and lens, all of which are either sealed within, or are a part of the envelope.

Shutter Blade: A single framing shutter.

Shutters: Short for Framing Shutters. A rectangular, metal apparatus that resembles a Venetian blind in form and function, generally used as a mechanical dimmer or blackout mechanism on large spotlights.

Side Light: Illumination of a subject from the side to place the subject in depth. A light source that provides such illumination.

Silk: Specifically, a fabric used for linear diffusion material it spreads the light linearly. It can be made from natural China silk or nylon. Generally, a scrim used in the film and video industries that is made from silk.

Single Ended Lamp: A lamp that has only one base and all of its contacts on the base.

Snoot: A cone-shaped accessory that mounts on the light to confine the beam to a very small spot.

Soft Edge: A beam pattern edge that is not very clear and distinguishable, i.e. one with a fuzzy or blurry perimeter.

Soft Light: Illumination that produces shadows with a soft edge. A light source that provides such illumination.

Solid: An opaque panel, usually made of fabric, placed into the beam of a light source to block a portion or the entire beam.

SP: A lamp designation that means spot.

Specular: A term used to describe a surface that is highly reflective or mirror-like the kind of hard light from a small, pinpoint light source.

Specular Light: See Hard Light, definition #1.

Spot: Short for Spot Light. The position of a focusable lamp, lens or pair of lenses on a spotlight that produces the most narrow field angle. To mark a location on which a light source will be focused. A term used to describe a round light pattern.

Spot Light: Generally, any of several types of light sources capable of emitting a beam pattern that is round, or in some instances, oval in shape, but more specifically this term refers to Fresnel spotlights, ellipsoidal spotlights and follow spots.

Spun Glass: A diffusion material made from glass fibers.

Stand Adapter: An apparatus used for mounting any one of a number of devices to a stand.

Strip Light: A multi-lamp light source with its lamps mounted in a straight row.

Strobe: Short for strobe light. See Flash.

Strobe Light: (Flash) A tube filled with xenon gas through which an electrical charge of high voltage is passed to create an electrical arc that emits a short, bright flash of light. Flash light is daylight balanced, usually measuring 5500° Kelvin. See Flash.

Stud: A metal protrusion, generally 3/8", 1/2", 5/8" or 1 1/8" in diameter. It is used to mount light sources and assorted grip equipment to a receiver such as a light stand. Studs also have wide, circular grooves designed to captivate the tip of the tee-handle or bolt provided with the receiver. This prevents the receiver-stud combination from unintentionally uncoupling, and can also prevent the stud from rotating once it`s seated. Any threaded metal protrusion used to mount light sources and assorted grip equipment via a nut or threaded socket.

Studio Fresnel: A Fresnel spotlight used primarily in studios for the film and video industries. Because portability is generally not a concern, these tend to be larger than location Fresnel`s of the same wattage.

Three-Point Lighting: The standard lighting system of key, fill and back lighting from which all other lighting setups evolve.

Transformer (Xformer): An item that converts voltage from one value to another. There are two basic types, electronic and magnetic, and both come in many configurations.

Translucent: A term used to describe something that transmits light, but scatters light rays so that a clear image cannot be seen through the material.

Transparent: A term used to describe something that transmits light without scattering light rays, so that a clear image can be seen through the material.

Tungsten: An element used to manufacture lamp filaments. It has a melting point of approximately 3400°.

Tungsten-Halogen: A term used to describe a family of lamps that use the halogen gas iodine, an envelope made of quartz, and a filament made of tungsten, in their manufacture.

Tweenie: A 300-650 watt Fresnel spotlight.

Twofer: A special power cord that has one male connector electrically connected to two female connectors via two separate cables or sets of sleeved wires.

Two-Pin Base: A lamp base with two narrow, parallel pin shaped contacts protruding from the bottom.

Ultraviolet (UV): A reference to anything that uses or emits ultraviolet radiation. Electromagnetic radiation having a wavelength longer than x-rays but shorter than violet light, approximately 40nm to 380nm.

Ultraviolet Light (UV Light): Although not actually light, this is a commonly used term for Ultraviolet Radiation.

Ultraviolet Radiation (UV Radiation): Invisible electromagnetic energy, of which the longer wavelengths are used to excite fluorescent materials. The wavelengths below 320nm are potentially harmful to human tissue.

Unit: A term that is often used interchangeably with light source.

Warm Color: Generally, a color that is in the yellow-orange-red range.

Warm Light: Light having a color temperature of approximately 2600°K3400°K, or yellow-white to red-white.

Wash: An even overall illumination covering a large area.

Wash Light: A light source used to produce a wash.

Watt (W): A unit of measurement for heat or electrical power.

Wavelength: The distance, measured in the direction of propagation, of a repetitive electromagnetic wave between two successive points.

Xenon: A gas used in some arc lamps that allows for a point source with extremely high luminous intensity and a color temperature of approximately 5500-6200°K.

Y Cable: See Twofer.

Zoom: Short for zoom focus. Some ellipsoidal spotlights and many follow spots have a zoom-focus system.

Zoom Focus: A term used to describe an optical system whereby the lenses in a light source adjust so that a beam pattern with a hard edge can be attained at various sizes at various distances without sacrificing beam lumens.