SUSU StageSoc
Southampton University Students' Union Backstage Society

Glossary :: Lighting

Animation Wheel: Very similar to a rotating gobo, but the center of rotation is outside the beam of the light. Often combined with a rotating gobo to give watery effects / fire effects.
Barndoors: These are used on the front of fixtures to mask off the edges of the beam of light to stop light shining on to things which need to be kept dark (e.g. certain parts of the stage, or the tabs).
Bender: A 13A to 15A adapter, used for plugging fixtures into 'normal' sockets.
Boom: As well as being a sound often produced by noise boys, this is also the name for a vertical lighting bar.
CeeForm: Term that describes a type of connector on power cables. Comes in 16A, 32A, 63A and 125A commonly. Red ones are three phase, blue ones are single phase.
CMY / RGB: Abbreviation for Cyan, Magenta, Yellow. A colour mixing system used in lighting fixtures. Essentially the inverse of RGB (Red, Green, Blue). RGB can be used with floods to create pretty much any colour needed on a cyc. for example.
Colour Wheel: Moving fixture equivalent of a scroller. It is a small wheel inside a fixture, which rotates in the beam of light allowing you to control the colour of the light. These do not use gels, since they would wear too easily.
Demux Unit: Not seen much nowadays as it is often intergrated into the dimmer or hard-wired and hidden in a dimmer rack. Device that changes analogue signals to dmx (digital) signals. Analogue cables used to take 6 channel signals in the same size cable that now takes 512 channels signals. You can think of it as the lighting equivalent of a set-top box.
Dimmer: A device that distributes power to the lighting fixtures. The amount of power to each fixture is goverened by the value specified for the fixture's channel on the DMX line.
Distro: Short for Distribution Unit: used to split up power in to combinations of smaller ampage outlets often used to producer single phase neutral power from three phase neutral power as well. Should be fitted with RCB trips.
DMX: Acronym of Digital Multiplex. This is the protocol that the dimmers, intelligent lights, and lighting desks use to communicate. DMX cable, comes in five or three pin versions, but the connections and protocol are the same. DMX cable is not the same as microphone cable, although mic cable can be used for short stretches.
Followspot: An oversized profile which is controlled by a followspot operator (in Luke's experience: very noisy / talkative people). Used to highlight certain actors, props, or parts of the stage during a show.
Gel: Used to be made of gelatin, hence the name. They are the sheets of coloured plastic used to colour light. You can get bored and order mini swatchbooks for the fun of it too!
Gobo: A shape or design that can be projected using a light by inserting a cut-out metal disk (sometimes made from apple-pie tins for cheapness Very Happy).
Gobo Rotator: This is another device, which can be put onto the front of a generic light, which allows a gobo to be rotated around its centerpoint.
Gobo Yoyo: A mechanism which allows gobos to be slid across the light.
Grelco: A two-way power splitter used on the 15 amp light 'sockets'.
Hard-patching: The act of assigning lighting desk channels to DMX addresses (dimmer channels usually), by physically swapping plugs/cables over. Soft-patching see lighting desk glossary.
Houselights: The standard lights you have on while the audience are coming in and out of the auditorium. These are usually a couple of floods (in Arts H's case: BEWARE - always use a gel mesh on them, and be prepared for people going "there's a burning smell". Don't dismiss it as being dust because the lanterns haven't been used for a while! You'll have lots of fun trying to hack the gel off the mesh, since it has melted itself on. Getting the mesh frame out of the floods seems to be harder than you'd expect!
Iris: This is a cleverly assembled device, which used (often in followspots), to change the size of the beam of light smoothly from a small aperture to a large one.
IWB: Internally Wired Bars. Basically a long scaff bar, with wires inside, and sockets along the length. If you're lucky, you get them like Arts H, where you have God knows how many phases going through one bar Tongue
Lampy: Generic term for lighting crew.
Limey: Little used term for follow spot operators, which stems from when stage light was created by burning lime - hence "lime light."
LX Tape / Spark Tape: PVC adhesive insulating tape, other wise known as PVC tape, insulating tape, LX tape or after a long get-in "insulting tape" (and often mistaken for Spike Tape by Stage Managers).
Scroller: This is a device, in which you take a lot of cuts of gel, and stick them together into one long scroll. You can then use a controller to scroll the gel around to the colour you want. This is handy when using limited fixtures, and being able to control the colour of them.
Shutters: Used in intelligent fixtures, the shutter is the piece of metal which can cover the whole beam. Depending on how good the fixture is, as you bring the shutter in, the light intensity will fade, or you will see the shutter come across the beam of light (having a semi-circle of light when the shutter is halfway in!)
Trelco: Like a grelco, but three-way rather than two.
TRS: Acronym of Toughened Rubberised Sheath. This is heat resistant cable used for providing power to light fixtures, that won't melt if it touches a light fitting.
Universe: A DMX universe consists of 512 channels of DMX data, which are sent down one DMX connection. If you have enough fixtures so that you are using more than 512 channels, or wiring restrictions mean that putting all the fixtures onto one DMX line would be hard, you can use multiple universes.

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