Glossary / kata-kata sukar dalam dunia lighting

12 07 2009

Dibawah ini ada beberapa kata-kata sukar dalam industri lighting. Maaf untitledkiranya bilamana masih dalam bentuk bahasa Inggris ( makhlum, saya sendiri awam dalam bahasa asing). Tapi mungkin beberapa hal tersebut bisa sedikit membantu, bagi anda yang kesulitan. Bilamana anda masih bingung, anda bisa membuka google translate atau transtool. Terimakasih.

13A PLUG
Standard domestic power connector in the UK. Three rectangular metal contacts (live, neutral and earth) with a fuse built-in (2A, 3A, 5A, 7A, 10A or 13A fuses are interchangable).

15A PLUG
Standard power connector in UK theatres. Three round metal contacts (live, neutral and earth); the principal difference from the domestic 13A connector is that the 15A version has no fuse.

A.J. / AJ
n. Jargon for an Adjustable Spanner. (UK) Known in the US as a C Wrench (short for Crescent Wrench).

A.L.D. / ALD
Association of Lighting Designers.(UK)
ALD Website

A1
Lighting Industry Forum code which identifies the (original) recommended usage of different lamp types. A1 coded lamps are for use in projection. See also CP, T, P2, K.

ABTT / A.B.T.T.
The Association of British Theatre Technicians.
ABTT Website

AC
Short for ALTERNATING CURRENT.

ACL / A.C.L.
Acronym for AirCraft Landing Light. See AERO.

ACN
Advanced Control Network. New show control protocol being developed by ESTA using ethernet. Designed to improve on the limitations of DMX512.
Historical overview of protocols

ADAPTOR
1) Connector which allows two or more electrical devices to be connected to a single power outlet. The connection is normally parallel, that is, each device is fed the same voltage, but the current is divided between them. Sometimes known as a ‘Twofer’. A three-way splitter is known as a ‘Threefer’. A Series splitter is also available where a voltage is shared equally between two loads.
2) Also an ADAPTOR can be the same as a JUMPER.
See SERIES SPLITTER, JUMPER and GRELCO.

ADB
(Manufacturer) Belgian manufacturer of lanterns, control desks and dimming equipment. Named after the initials of it’s founder, Adrian de Backer.
ADB website

ADB 62.5
Near-obsolete digital lighting control protocol developed by ADB. Uses a 5 pin XLR connector but is NOT compatible with DMX512

ADDITIVE COLOUR MIXING
See COLOUR MIXING.

ADDRESS*
Each item of equipment controlled by DMX512 has an address, which is the first DMX control channel to which it will respond. For example, in a situation where you have three 6-way dimmer racks, the first should be addressed to 1, the second to 7 and the third to 13.

ADJUSTABLE SPANNER
See A.J.

ADVANCE BAR
Lighting bar positioned just downstage of the proscenium arch. Also known as ANTI PROSCENIUM.

AERO
A type of high intensity Par lamp that derives its name from its use as an aircraft landing lamp. The true Aero is 28V and 250W, although there are many variations. The lamp has a very tight beam.

ALPHAPACK
(Trade Name) Portable 3 way dimmer pack manufactured by Zero 88.
Zero 88 website

ALTERNATING CURRENT*
An electric current that reverses direction in a circuit at regular intervals. Abbreviated to AC. UK mains electricity is AC and changes direction 50 times per second (that is, the frequency is 50Hz).
See also DIRECT CURRENT.

AMPERE
The standard unit for measurement of electrical current passing through a circuit (usually abbreviated to AMP). Written as ‘I’ in equations. Cables, fuses and switches are designated by their current carrying capacity. (Following phrase refers to UK standards). Square pin plugs are rated at 13 Amps maximum and Round pin plugs at either 5 Amps or 15 Amps maximum, depending on the size of the pins. If a cable rated at 5 Amps is used with a load of 15 Amps (for example), the cable will overheat and possibly catch fire.

AMX-192
See MULTIPLEXED SIGNAL.

ANALOGUE SIGNAL
A continuously variable signal that can have any value over a given range.
1) In lighting: an analogue voltage within the range 0 to 10 Volts can have values of 0, 2, 8.785 or any value between. Most dimmers require an analogue voltage in order to operate (from 0 to -10V or 0 to +10V depending on the manufacturer). Most lighting control desks produce a digital multiplexed output, which is converted by a demux box to an analogue signal for the dimmer. See also Digital dimmer.
2) Sound: An analogue recording will record the exact waveform of the original sound, simply converting it to an electrical signal at the microphone, and back into air movement at the speaker. See DIGITAL.

ANGSTROM
Unit of measurement of length (e.g. for wavelengths of light). 1 Angstrom is equal to one ten billionth (1 x 10-10) of a metre. The unit is named after the Swedish physicist Anders J. Ångström.
See WAVELENGTH.

ANIMATION DISC
See EFFECTS.

ANSI / A.N.S.I.
American National Standards Institute. Three letter ANSI codes are used in the US to identify lamps.
ANSI website

ANTI PROSCENIUM
Originally Ante Proscenium, meaning in front of the proscenium.
See ADVANCE BAR.

APOLLO DESIGN TECHNOLOGY
(Manufacturer) US-based manufacturer of gel, gobos, effects and scrollers.
Apollo Design Technology Inc. website

ARC LIGHT
See DISCHARGE LAMP.

ARCHITECTURAL LAMP
A type of linear filament lamp with contacts at 90 degrees to the filament which can gives the appearance of a continuous line of light (similar to neon, but dimmable).

ARCLINE
(Trade Name) A coloured plastic tube containing a number of small strobe units which, when triggered, flash in sequence down the tube. Many tubes can be connected together.

ARRI
(Manufacturer) German/US manufacturer of film lighting and cameras (Arriflex). Founded in 1917. Previously, Arri made a range of lighting desks (including Imagine, Impulse, Mirage, Microlux) which were early versions of desks now produced by ETC. ETC took over the lighting control side of Arri in 1995.
ARRI website

ARTISAN
(Trade Name) Moving light control console made by Vari*Lite.
Vari*Lite Website

ARTNET
Ethernet-based lighting control protocol, developed by Artistic Licence. ArtNet can carry up to 256 DMX512 universes on the ethernet saving on cable runs. With the development of wireless networking the possibilities are endless.
Artistic Licence website

ATTRIBUTES
The controllable parameters of a moving light are known as the ATTRIBUTES. All moving lights will have pan & tilt, with many having colour wheels, gobo selection, gobo rotation etc. as additional attributes.

AUTOMATED FIXTURE
See MOVING LIGHT.

AVOLITES
(Manufacturer) UK-based manufacturer of lighting control consoles (Azure, Pearl, Sapphire, Diamond) and dimmers.
Avolites website

AWG
American Wire Gauge. US system for measuring the thickness of wire. The lower the number, the thicker the wire.

BACK PROJECTION
See PROJECTION.

BACK-UP
A section of a lighting control board (sometimes a separate unit) which provides an alternative method of control should the main board fail.

BACKLIGHT / BACK LIGHT
Light coming from upstage, behind scenery or actors, to sculpt and separate them from the background

BAFFLE
1) A sheet of material used to prevent a spill of light in a lantern or in part of a set.
2) A panel in a loudspeaker cabinet designed to reduce back interference noise by isolating the front and rear of the loudspeaker diaphragm.
3) A panel in an auditorium positioned so as to reduce sound reflections and improve the acoustics of the space.
4) What most of this jargon will do to any non-technical theatrical type.

BAKELITE
(Trade Name) Early type of thermosetting plastic often used for electrical plugs and sockets. Has a distinctive fishy (ammonia) smell when burning.

BALCONY RAIL
See CIRCLE FRONTS.

BALLAST
A unit used in conjunction with discharge lamps containing capacitors, inductors and other start-up circuitry. The inductor is initially used to develop a high potential (voltage) to strike the discharge and is then used to limit the current flow while the lamp is lit.

BALLYHOO
(US) Swinging a followspot beam around in a figure of eight pattern. A more random effect is sometimes known as an RKO (after the searchlights used in the RKO Pictures movie logo.

BAR
The horizontal metal (steel or alloy) tube (usually 48mm in external diameter, but can be up to 60mm) hung from flying lines (or forming part of a grid) from which lighting equipment and scenery etc. may be suspended. Also known as a BARREL. When vertical, known as a BOOM. Sometimes known as a PIPE in the US, although many curse that usage, and demand the use of Batten ; ‘A pipe is what you smoke; a batten is what you hang your instruments from.’.
Language, especially in theatre, is rarely universal!

BARE ENDS
Term to describe an electrical cable which has no connector at one end (for example, a SPEAKON to BARE ENDS cable is used to connect the terminals of a speaker cabinet to a speakon socket, and a 63A socket to bare ends might be used to wire in a temporary supply from a power distribution board before connecting equipment. Any installation work of this sort should only be carried out by a qualified electrician, and should never be done ‘live’.

BARN DOORS
See BARNDOORS

BARNDOORS
A rotatable attachment consisting of two or four metal flaps (hinged) which is fixed to the front of a Fresnel or PC type lantern to cut off the beam in a particular direction(s).
Profile lanterns use SHUTTERS to achieve a greater degree of control and accuracy.
Barndoors are also available for parcans and birdies. BLACKWRAP can be used to reduce additional light spill where barndoors aren’t doing the job.

BARREL
See BAR.

BASE PLATE
A metal plate which prevents damage to floors when using scaffolding or trussing.

BATTENS
1) Timber at the top and bottom of a cloth. A Sandwich batten is used to carry a hanging cloth. It comprises two flat pieces of timber screwed together with the edge of the cloth between them.
2) Timber used for joining flats together for flying.
3) Compartmentalised floodlights set up so as to allow colour mixing. See also GROUNDROW. Low voltage battens are commonly used as light curtains & for colour washes. Known in the US as a STRIPLIGHT.
4) US term interchangable with PIPE for a flying bar.

BAUD
(Bits per second) Measurement of the speed of electronic communications protocols. DMX512 operates at 250,000 baud (i.e. 250,000 electronic signal changes per second).

BC HOLDER
Type of UK domestic lampholder that has largely been replaced by the ES (Edison Screw) and the GES (Goliath Edison Screw) for general lighting applications in the theatre. Stage lighting equipment uses prefocus lamp bases. (Most types of Festoon still use BC holders.)

BEAM ANGLE
The angle of the cone of light produced by a lantern. Defined as the angle within which the lowest intensity in a beam of light from a lantern is not less than one-tenth of the maximum.

BEAMLIGHT
Flood lantern which uses a parabolic reflector and a low voltage high intensity lamp to produce an intense near-parallel beam. Also known as a Beam Projector.
A PARCAN is a special type of beamlight.

BECTU
Broadcasting, Entertainment, Cinematograph and Theatre Union. The UK entertainment technicians union. (US equivalent is IATSE)
BECTU website

BEGINNERS
A call given by Stage Management to bring those actors who appear in the first part of a play to the stage. e.g. ‘Act One Beginners to the stage, please’. The actors/actresses are then called by name.
A similar call is given after the interval (e.g. ‘Act Two Beginners to the stage please’). See also HALF, QUARTER.

BELTPACK
Part of the communication (‘cans’) system in a theatre, the Beltpack contains the controls and circuitry to drive the HEADSET worn by crew members. Each beltpack connects into the headset ring and back to a PSU (Power Supply Unit) which is powered from the mains.
See also CANS.

BETAPACK
(Trade Name) Portable 6 way dimmer pack manufactured in the UK by Zero88.
Zero 88 website

BIFOCAL SPOT
Profile lantern with two sets of shutters, one of which produces a hard edge, and one a soft edge. Not necessary in zoom profiles, because this requirement is fulfilled by two lenses.

BINARY*
BIT = Binary Digit. More information coming soon.

BIOBOX
(Aus) Australian term for the lighting control booth at the rear of the auditorium. Shortened version of BIOGRAPH BOX, after it’s original function as a cinema projection box. Sometimes also known as the DOME if followspots are controlled from the same position.

BIRDIE
A compact low voltage display luminaire containing a Par 16 or MR16 lamp. So called because it is similar to, but much smaller than, the Parcan, and is hence ‘one under Par’. (It’s a golfing reference). Requires a 12 Volt external transformer, but is ideal for concealing in pieces of set or as downstage uplights.
See also MR16.

BLACK HOLE
Accidentally unlit portion of the stage.

BLACK LIGHT/BLACKLIGHT
See ULTRA-VIOLET.

BLACKOUT / BO / B.O.
1) Complete absence of stage lighting. Blue working lights backstage should remain on and are not usually under the control of the board, except during a Dead Blackout (DBO), when there is no onstage light. Exit signs and other emergency lighting must remain on at all times.
2) The act of turning off (or fading out) stage lighting (e.g. ‘This is where we go to blackout’)

BLACKWRAP
(Trade Name) Thin black aluminium product which is used to temporarily mask light coming out of a luminaire’s body, or to control spill. A self-adhesive tape version is also available.

BLEECON
Trade name for a type of low voltage 8 pin connector which is similar to the audio DIN plug. Used most often for carrying signals from analogue lighting control desks to dimmers or to demux boxes. Originally manufactured by Belling and Lee, hence BLEEcon (for connector).

BLEED THROUGH
Transformation from a scene downstage of a gauze to another scene upstage, by slowly crossfading lighting from downstage to upstage. If a gauze is lit steeply, or from the sides, it will appear solid. If this light is turned off and light added to the set upstage of it, it will disappear.

BLEEDING
1) Dimmers which are incorrectly trimmed are said to bleed. That is, the dimmer still gives a small output, causing the lantern to glow, when the control signal is at a minimum.
2) A contrasting colour paint still showing through a newly-applied top coat is said to be bleeding.

BLIND PLOTTING
The facility on some lighting control desks for the operator to make changes to the plot, without affecting the state on stage.

BLINDERS
Lamps arranged around the stage directed into the auditorium, originally to prevent spectators seeing the stage during scene changes when the house tabs were not lowered. Now used for effect in rock concerts etc.

BLONDE
2000W open-faced flood lamp used in film / TV lighting. So-called because of it’s yellow/gold paint finish. See also REDHEAD.

BLUES
Blue lights used backstage in a performance situation. See also working lights.

BNC
Coaxial connector used for carrying a composite video signal or radio frequency signal. BNC stands for Bayonet Neill Concelman – after original inventors Carl Concelman and Paul Neill who developed the connector in the late 1940s. BNC is also thought to stand for ‘Bayonet Nut Connector’.

BOARD
The main control for the stage lighting. Originally known as the switchboard or dimmerboard, it is now usually remote from the dimmers. The lighting operator for a show is said to be ‘on the board’, and is sometimes known as the ‘board op’.
Known in the US as the Light Board.

BOMB TANK
Metal bin or box covered with fine mesh in which Theatrical Maroons can be safely detonated.
See also PYROTECHNICS.

BOOM
1) Vertical scaffolding pole (usually 48mm diameter) on which horizontal boom arms can be mounted, carrying lanterns. Often used behind wings for side-lighting etc. Booms have a base plate (known as a TANK TRAP) or stand at the bottom and are tied off to the grid or fly floor at the top (not always necessary for short booms). Booms can also be fixed to the rear of the procenium arch (Pros. Boom) or hanging from the ends of lighting bars. Sometimes known in the US as a light tree. A light tree mounted upstage of a Tormentor is known as a Torm Tree.
2) An arm mounted on a microphone stand.

BOOM ARM
See BOOM.

BOOM BASE
A wooden board with vertical scaffold tube adaptor used as a base for lighting booms. Although the base provides a degree of support (especially with added brace weights) booms often require additional support from above.
Sometimes known as a TANK TRAP, as it’s very hard to drive a tank over a boom base?

BOOMERANG
1) See COLOUR CHANGER.
2) Old name for a BOOM (vertical lighting position).

BOOTH
(US) Control Room.

BORDER
A narrow horizontal masking piece (flattage or cloth), normally of neutral colour (black) to mask the lighting rig and flown scenery from the audience, and to provide an upper limit to the scene. Often used in conjunction with LEGS.

BOUNCE
1) Diffuse light that has been reflected from the stage, walls, cyclorama etc.
2) ‘Bounce’ is sometimes used for a flat (non-curved) cyclorama. Strictly, a bounce is a white or light blue cloth onto which light is bounced to backlight another cloth. A bounce doesn’t need to be seamless, whereas a cyclorama should be.
3) Describes the fast in/out movement of ‘bouncing’ flown house tabs, used during curtain calls. This can also apply to the fast blackout/lights up cues that happen at curtain calls.
4) This facility is available on many multitrack tape machines. Describes the mixing down of multiple sounds from different tracks onto one track, hence freeing up the other tracks to be re-used. Allows many sounds to be recorded onto one tape.

BOWENS
Short for Bowens Flash Unit. Instrument which produces a bright white flash when triggered. Used by professional photographers. Unlike a STROBE, the Bowens unit needs to charge up between flashes (around 10 seconds) so is unsuitable for the same applications, but is ideally suited for recreating bright lightning flashes on stage.

BOX
Lighting Box – see CONTROL ROOM.

BOX BOOM
US term for a front of house vertical lighting position (predominantly sidelight as the booms are rigged from the boxes nearest the proscenium arch).

BOX TRUSS
See TRUSS.

BRAIL
A horizontal rope, wire or chain attached at either end of a piece of scenery or lighting bar pulling it upstage or downstage of its naturally hanging position to allow another flying item to pass, or to improve its position. See also BREAST LINE.

BREAKOUT
A connection at the end of a multicore cable which allows the connection of many items to it. (e.g. there is a breakout box at the end of a sound multicore cable which allows you to plug microphone cables into it).

BREAKUP
A commonly used abstract GOBO which gives a textured effect to the light, without throwing a specific pattern onto the stage. Used to add interest to light beams. A leafy breakup is used for outdoor scenes / forests / spooky wood etc. to break up the light on the actors faces.

BRIDGE
A walkway, giving access to technical and service areas above the stage or auditorium, or linking fly-floors. See also CATWALK.

BSI
British Standards Institute.

BUBBLE
1) (especially TV and Film) Jargon for a replacement lamp.
2) The glass part of a lamp.

BUILD
1) During lighting plotting, to construct a state from blackout, or to add to an existing state.
2) An increase in light or sound level. See CHECK.
3) A period of set construction (‘The Build’).

BULB
See LAMP.

BULGIN
Range of connectors used for multipin or ‘non-standard’ connections. The small 3 pin Bulgin plug is used on the Le Maitre Pyroflash system. The larger 8-pin round ‘truck plug’ allows the connection of 6 dimmer circuits (up to 6A each) via a single multicore cable. This is ideal for carrying multiple dimmed circuits to a moving set-piece or truck. The 8-pin round connector has become a standard for disco lighting systems.
Bulgin Components website

BUMP
A flash or sudden jump in light level (a snap cue) (see also FLASH BUTTON).

BUMP CUE
A lighting cue that instantly bumps the lighting up to a brighter level. Usually at the end of a musical number to draw the applause.

BURNT OUT
A coloured gel that has lost its colour or melted through due to excessive heat in front of a lantern. Dark blues and greens etc. are most susceptible, and may need replacing during a long run.

BUSBAR
Metal bar carrying incoming electrical supply into which portable dimmer racks or other large power requirements can be wired directly. An enclosure containing busbars is a Busbar Chamber.

C CLAMP / C-CLAMP
US equivalent of the UK Hook Clamp. Requires a spanner/wrench to tighten. Known as a PARROT CLAMP in the US film business.

C-WRENCH
US for SPANNER. (Abbreviation of Crescent Wrench).
See CRESCENT WRENCH

C.C.T.V. / CCTV
Closed Circuit television. A video relay system, used in the theatre to give a view of the stage to remote technical operators (especially stage managers). Also used to give musical performers a view of the conductor (and vice versa) to help in keeping time. It’s called Closed Circuit because the signal is not being broadcast anywhere – there’s a direct link between camera and monitor.

CABLE
Wiring, temporarily rigged, to carry electrical current. Depending on the size of the cable (current carrying capacity), cables are used to supply individual lanterns, whole dimmer racks, or carry signals from a microphone etc.

CABLE GRIP
A U-shaped clip and saddle used for terminating wire rope. Also known as a Bulldog, Dog Grip or Wire Rope Clip.

CABLE TIE
Lockable (and sometimes releasable) plastic strap used to tie a bundle of cables together, amongst many other things.

CAD
Computer-Aided Design. Using a computer to help with 2D plans and drawings, or increasingly for 3D visualisation of how a set will look, and how lighting will affect it. See also WYSIWYG.

CALLING THE SHOW
The process of giving verbal cues to the lighting, sound, fly operators and stage crew during the performance. Usually done from the prompt corner by the DSM or Stage Manager over cans.

CAMLOCK
(Trade Name – Crouse Hinds – CAMLOK) Single pole connector used on professional power distribution & dimming systems. A separate connector is used for each phase/neutral of the supply.Originally developed for touring concerts, as power demands increase it’s finding more use in theatres.

CAN
Advanced Control Network. A new (2003) ethernet-based control protocol between control desk, dimmers & moving lights. Developed by ESTA and Strand Lighting. DMX nodes are used to communicate with non-ethernet devices.

CANS
1) Headset earpiece, microphone and beltpack used for communication and co-ordination of technical departments during a performance. (e.g. ‘Electrics on cans’, ‘Going off cans’, ‘Quiet on cans!’ ).
The common system in the UK is produced by Canford Audio under the TechPro brand. In the USA, ClearCom is commonly used.
2) Any headphones.
3) Short for PARCANs.

CANTATA
(Trade Name) Range of 1200W lanterns produced by Rank Strand (now Strand Lighting) in the UK.
Strand Lighting website
Strand Archive

CAROUSEL
Circular slide magazine; also refers to a 35mm slide projector using this type of magazine (Kodak trade name). See PROJECTION.

CAST LIGHTING
Canadian creators of WYSIWYG software.
Cast Lighting website

CASUALS
Part-time temporary technicians (paid by the hour).

CHAIN HOIST
Manually operated or electrically driven hoist for lifting scenery and lighting equipment. The chain hoists are rigged to fixed points in the venue. Commonly used to lift lighting truss into position for touring shows or concerts.

CHANNEL
A complete control path for signals in lighting or sound equipment.
In a lighting desk, the channels are directly controllable by the lighting operator. Within the desk, the channels are ‘patched’ to a dimmer or dimmers which the desk then sends a signal to depending on the level of the channel.

CHASE
A repeated sequence of changing lighting states. A chase can be produced easily by the effects functions of a computerised lighting desk. There are standalone units designed to chase lighting circuits electronically in time to music (sound to light) or mechanically as a repeated sequence (as used in early neon signs).

CHEAT SHEET
A smaller version of the lighting plan, used by the lighting designer during the lighting plot. Also known as a Dimmer Layout or Magic Sheet.

CHECK
1) Opposite of Build; a smooth diminishment of light or sound level (e.g. Lighting: ‘I think we should check this state down a touch as the song begins’)
2) See Prefade Listen.

CHIAROSCURO
(n.) In Lighting or Scenic design (and the Art world), Chiaroscuro means the use of contrasts of light and shade, especially in order to enhance the depiction of character and for general dramatic effect. Many painters are said to be masters of Chiaroscuro (especially Rembrandt, Caravaggio etc.) From the Italian words chiaro ‘clear, bright’ and oscuro ‘dark’. From the Random House Word of the Day website.

CHIEF ELECTRICIAN
The senior member of the theatre’s stage lighting team, although not necessarily the lighting designer. Known in the US as MASTER ELECTRICIAN.
In common with many theatre jobs, the actual duties of the Chief Electrician vary from theatre to theatre. Some chiefs are responsible for electrical maintenance of the building, some design the lighting for nearly every in-house production, some design no lighting at all, some have a team of eight staff under them, some have two. Many theatres employ casual staff to assist on lighting rigging sessions. Some theatres have a separate sound department, smaller venues have the lighting team also running sound for shows (and doing sound design for some).

CHINAGRAPH PENCIL
Usually white, wax-based pencil used for marking magnetic tape prior to splicing. Also used for marking identifying numbers on lighting gels.

CHOPPERS
(Followspot term) Two horizontal masking shutters used in followspots to shape the beam above and below.
Submitted by Bert Morris.

CID
(Compact Iodide Daylight) A high intensity discharge lamp that produces a light similar in colour temperature to daylight approx. 5500K). A 1000W CID lamp produces 2.5 times more light than a 2000W tungsten halogen source.

CIE
(Commission Internationale d’Eclairage) International lighting forum which has produced (amongst many other things) a series of universally recognised symbols for lighting plans.
CIE website

CIRCLE FRONTS
A permanent front of house lighting position in older proscenium theatres. A number of spotlights, sometimes fitted with colour changers, are recessed into the front of the circle balcony above the stalls. Sometimes known as the Balcony Rail position.

CIRCUIT
1) The means by which a lantern is connected to a dimmer or patch panel. Numbered for reference.
2) A complete electrical ‘loop’ around which current can flow.

CIRCUIT BREAKER
An electro-mechanical ‘fuse’ that can be reset, rather than having to be replaced. Available in the same ratings as fuses. See MCB, RCD.

CITT
Canadian Institute for Theatre Technology.
CITT website

CLEANERS
Auditorium working lights. Used for cleaning and setting up the auditorium before the house lights (usually more atmospheric) are switched on.

CLOVE HITCH
Invaluable knot that every technician should know.

CMY
Cyan / Magenta / Yellow – the three secondary (additive) colours of light which are used in moving lights for colour mixing. Some cheaper systems use three graduated colour scrolls (one of each colour) in front of a standard fixture, but these take a massive amount of intensity out of the beam, resulting in a dim light on stage. Many moving lights use a similar system with dichroic colours which are more efficient and longer-lasting.

COLOR
See COLOUR FILTER.

COLOUR
See COLOUR FILTER.

COLOUR CALL
A list compiled from the lighting plan of all the colours needed for the rig, and their size. This term also applies to the act of preparing colour filters and frames from such a listing.

COLOUR CHANGER
1) Scroller, where a long string of up to 16 colours is passed horizontally in front of a lantern. Remotely controlled by the lighting desk. Some scrollers have cooling fans to prolong the life of the gel string. Stronger colours will burn out faster without cooling, or if the focus of the beam is concentrated on the gel. If colours aren’t lasting very long in scrollers, try changing the focus of the lantern. HEAT SHIELD clear gel should be used between the lens and the colour scroller to absorb some of the heat.
2) Wheel : Electrically or manually operated disc which is fitted to the front of a lantern with several apertures holding different colour filters which can be selected to enable colour changes. Can also be selected to run continuously.
3) Semaphore, where framed colours are electrically lowered into place in front of the lantern. Remotely controllable. Can perform additive colour mixing by lowering two colours into position at the same time.
4) Magazine : Manual semaphore-type device used on the front of a followspot. Known in the USA as a BOOMERANG.

COLOUR CORRECTION
The use of colour filters to compensate for the different colour temperatures of different light sources. Important in lighting for TV and film.

COLOUR FILTER
A sheet of plastic usually composed of a coloured resin sandwiched between two clear pieces. The coloured filter absorbs all the colours of light except the colour of the filter itself, which it allows through. For this reason, denser colours get very hot, and can burn out very quickly. There are a number of manufacturers of Colour Filters – Lee (UK), Rosco (US), Gam (Great American Market – US) and Apollo (US) are some of the more popular. Each manufacturer’s range has a numbering system for the different colours. It’s important to specify which range you’re talking about when quoting numbers.
A colour filter is sometimes known as a Gel, after the animal material Gelatine, from which filters were originally made.
Lee Filters website
Rosco website
GAM website
Apollo Design Technology website

COLOUR FRAME
(or Gel Frame) A frame which holds the colour filter in the guides at the front of a lantern. Many different sizes of frames are needed for the different lanterns.

COLOUR MIXING
Combining the effects of two or more lighting gels:
1) Additive : Focusing two differently coloured beams of light onto the same area (eg Cyc Floods). Combining colours in this way adds the colours together, eventually arriving at white. The three primary colours additively mix to form white, as do the complementary colours.
2) Subtractive : Placing two different gels in front of the same lantern. Subtractive mixing is used to obtain a colour effect that is not available from stock or from manufacturers. Because the ranges of colour are so wide, the need for subtractive mixing is reducing. Combining colours in this way reduces the light towards blackness. The three primary colours mix subtractively to form black (or to block all the light).
More on Colour Mixing

COLOUR SCROLLER
See COLOUR CHANGER.

COLOUR TEMPERATURE
A measure of the ‘warmth’ or ‘coolness’ of light sources and colours. Measured in degrees Kelvin. A higher colour temperature light source will appear whiter (colder). The human brain automatically compensates for different colour temperatures – a film or video camera cannot, and thus what we see as white may appear to have a blue or green tint when no colour correction is used for video. Most video cameras have a ‘White Balance’ control to make colour temperature adjustments, to ensure white looks white on camera.
Daylight is approximately 5600°K, Tungsten Halogen is approx. 3200°K and standard incandescent lamps are 2800°K. Many discharge light sources are in use in modern theatrical productions using discharge followspots or moving lights – colour correction filters are used to balance the colour temperatures.
See also COLOUR CORRECTION.

COLOUR WHEEL
See COLOUR CHANGER.

COMPLEMENTARY COLOURS
Pairs of colours which, when additively mixed, combine to produce white light. Examples are red + cyan, green + magenta, and yellow + blue.

COMPOSITE GOBO
See GOBO.

CONCAVE
Lens shape. Edges are wider than the centre of the lens. Useful to remember that ‘caves’ go inward.

CONDENSER LENS
Loosely applied to any spotlight lens which condenses diverging rays into a beam, but more correctly to the short focus combination of two or more lenses in a jacket used for illuminating a slide or effect disc. Also used in some profile lanterns and followspots to produce a smoother light (especially for gobo work).

CONDUIT
Metal or plastic pipe used to carry electrical conductors as part of a permanent electrical installation. See also Trunking.
Also used to add weight to the bottom of a flown cloth.

CONTROL ROOM
Room at the rear of the auditorium (in a proscenium theatre) where lighting and sometimes sound is operated from. Known in the US as the BOOTH. The stage manager calling the cues is very often at the side of the stage (traditionally stage left) but in some venues he/she may be in the control room also. The control room is usually soundproofed from the auditorium so that communications between operators cannot be heard by the audience. A large viewing window is obviously essential, as is a ‘show relay’ system so that the performance can be heard by the operators. Obviously if sound is being mixed, the operator should be able to hear the same as the audience, so some control rooms have sliding or removable windows, or a completely separate room for sound mixing. Where possible, the sound desk is moved into the auditorium so that the operator can hear the same as the audience.
Also known as the BOX.

CONVEX
Lens shape. Edges are thinner than the centre of the lens.

COOKIE
See GOBO.

COSTUME PARADE
See DRESS PARADE.

COVE
US for front of house catwalk lighting positions. Also ‘Balcony Rail’.

CP
Lighting Industry Forum code which identifies the (original) recommended usage of different lamp types. CP coded lamps are for Film, Television and Photographic studio use and have a colour temperature of 3200°K. See also A1, T, P2, K.

CRACKED OIL
A smoke effect which creates a haze in the air to make light beams visible. This effect is rarely used now, because it has been found to be carcinogenic. See Water Cracker.

CRESCENT WRENCH
(US) A open ended adjustable hand wrench originally produced by the Crescent Tool Co. Known as a C-WRENCH.

CROSBYS
US for saddle and ‘U’ cable clamps (from the manufacturers name).
Crosby Group website

CROSS FADE
Bringing another lighting state up to completely replace the current lighting state. Also applies to sound effects / music. Sometimes abbreviated to Xfade or XF.

CSI
(Compact Source Iodide) A high intensity discharge lamp. Most often used in followspots, because it has a colour temperature (approx. 4000K) close to that of the tungsten halogen lamps.

CUE
1) The command given to technical departments to carry out a particular operation. E.g. Fly Cue or Sound Cue. Normally given by stage management, but may be taken directly from the action (i.e. a Visual Cue).
2) Any signal (spoken line, action or count) that indicates another action should follow (i.e. the actors’ cue to enter is when the Maid says ‘I hear someone coming! Quick – Hide!’)

CUE LIGHT
System for giving technical staff and actors silent cues by light. Cue lights ensure greater precision when visibility or audibility of actors is limited. Sometimes used for cueing actors onto the set. For technical cues, lights are normally now used just as a backup to cues given over the headset system. In the UK, a flashing Red light means stand-by or warn, green light means go. The actor / technician can acknowledge the standby by pressing a button which makes the light go steady. In the US, a red light means warn, and when the light goes off, it means GO. The UK system seems to be more secure, but it depends what you’re used to.

CUE STACK
Section of a lighting desk which allows a list of pre-plotted lighting states to be ‘played back’ on the push of a button. These lighting states normally have fade times allocated to them. Lighting desks designed for theatrical use will have this as the primary control, but a rock desk will have more ‘hands on’ control as a priority, only providing a cue stack for occasional use.

CUE TO CUE
(‘Topping and Tailing’) Cutting out action and dialogue between cues during a technical rehearsal, to save time.

CUEING
There is a standard sequence for giving verbal cues :

  • ‘Stand-by Sound Cue 19′ (Stand-by first)
  • ‘Sound Cue 19 Go’ (Go last).

CURRENT
The flow of electricity (electrical charge) through a circuit. Measured in Amperes (Amps)

CYC FLOOD
A floodlight, usually with an asymmetrical reflector, designed to light a cyc or backcloth from the top or bottom. The asymmetric reflector helps to throw light further down the cloth, producing a more even cover. In the US, a flood at the top of the cyc is a CYC OVER, and a flood at the bottom is a CYC UNDER.
Types of lantern

D54
See MULTIPLEX.

DAISY-CHAINING
Connecting items of equipment together by linking from one to the next in a chain. Used for connecting demux boxes to dimmers etc.

DANCE LIGHTING
Lighting design for Dance is reliant on a great deal of sidelight from BOOMS at the side of the stage. There are normally at least three lanterns on each boom, and three heights – SHINS (to light feet and lower legs), MIDS and HEADS.

DBO (Dead Blackout)
See BLACKOUT.

DC
Short for DIRECT CURRENT.

DE-RIG
The process of removing lanterns & cabling from flying bars or grid – returning the venue to it’s normal state, or as preparation for the next production.

DEAD
1) A pre-plotted height for a piece of scenery or lighting bar – ‘that bar’s on its dead’. The positional indicators on the rope (either PVC tape, or more traditionally cotton tape passed through the strands of the rope) are called DEADS. Sometimes flying pieces are given a number of extra deads, that may be colour coded, in addition to the ‘in dead’ (lower) and ‘out dead’ (higher – out of view). In the US, TRIM has the same meaning.
2) Scenery or equipment not needed for current production – ‘that table’s dead’.
3) An electric circuit that has been switched off or has failed – ‘the circuit’s dead, you can change the lamp now’
Submitted by Chris Higgs

DEMUX BOX
Interface unit between the serial digital output of a memory lighting control desk to the parallel analogue signal understood by a non-digital dimmer. See MULTIPLEX SIGNAL for more.

DESIGNERS CONTROL
See RIGGERS CONTROL.

DIAPHRAGM
1) See IRIS.
2) The part of a microphone which responds to sound waves.

DICHROIC FILTER
Glass colour filters which reflect all light except that which is the colour of the filter, which passes through. Normal plastic gels absorb the unwanted colours, turning the light into heat. Dichroic filters run cooler, and produce a much cooler beam of light. Longer lasting, but a lot more expensive, they are predominantly used in moving lights or architectural applications.

DICHROIC LAMP
A low voltage display lamp with a reflector that lets heat pass through it, rather than reflecting it. Results in a much ‘cooler’ light.

DIFFUSION
See FROST.

DIGITAL
Many electronic devices use digital logic. Information is handled in separate bits (either ON or OFF) rather than continuously variable analogue signals. Most computer lighting boards give a digital multiplexed output, and more and more sound equipment is going digital.

DIGITAL DIMMER
The new generation of dimmers that can respond directly to the digital multiplexed output of the lighting desk. The technology also permits the dimmer to report faults and other data back to the control board.

DIGITAL LIGHT CURTAIN / DLC / D.L.C.
A remotely controllable motorised batten fitted with an integral colour changer. The DLC can now be controlled via DMX (via an interface) although it originally used software called Light Moves running on a Mac. The effect produced by this lantern is a wall of light (when used with a HAZE MACHINE). See also LIGHT CURTAIN.
DHA Lighting website – Digital Light Curtains

DIM OUT
Reduction of lighting level for a scene change, that isn’t quite a BLACKOUT.

DIMMER
Electrical or electronic device which controls the amount of electricity passed to a lantern, and therefore the intensity of the lamp.

DIMMER DOUBLING
A system designed by ETC where two ETC lanterns can be connected to a single ETC dimmer, and have different intensities. It only works with 115V / 60Hz supplies (e.g. USA). A special adapter (‘twofer’) is connected to the dimmer output. This contains a series of diodes which split the AC sine wave into two halves (positive and negative). Each half is sent to a separate socket on the adaptor and from there to a modified ETC Source Four lantern with a 77 volt lamp. Using these lower voltage lamps means that full intensity is achievable using only half the AC wave. The system will not work in the UK or other countries with 50Hz power supplies as the flickering of the lamps is too noticeable.
Dimmer Doubling information on ETC website

DIMMER LAW (Control desk)
The dimmer law in a lighting desk defines the relationship between the control value (fader position) and the console output value (outgoing DMX level).
Submitted by Andre Broucke

DIMMER LAW (Dimmer)
The dimmer law defines the relationship between the incoming DMX control value and the dimmer output RMS voltage. Common dimmer laws are ‘linear RMS voltage’ and ‘linear light output’. Around the rated lamp voltage the light output is quite sensitive to voltage variations (a slightly lower voltage can also improve lamp life). If the dimmer is set to ‘linear light’ and you fade from 100% to 95%, the light output will be reduced by 5%. If you set the dimmer to ‘linear RMS voltage’ and you fade from 100% to 95%, the light output will be reduced by more than 5%.
Submitted by Andre Broucke

DIMMER LAYOUT
See CHEAT SHEET.

DIMMER PER CIRCUIT
A lighting installation where there is no patching system. Each lighting circuit / socket has a dimmer always connected to it. This has advantages in that you never run out of dimmers, but allows no flexibility and can have cost disadvantages in a large space.

DIMMER RACK
A number of individual dimmer circuits mounted in a cabinet.

DIMMING SHUTTER
Mechanical way of dimming the light output from a discharge lamp or projector when dimming the lamp is not possible. Consists of a series of horizontal blades which are rotated to reduce and then cut the light completely. See also DOWSER/DOUSER.

DIN
Deutscher Industrie Normen. European standard covering audio connectors and tape equalisation characteristics.

DIP
1) Small covered trap at stage level containing electrical outlets. (US equivalent is FLOORPOCKET)
2) Lighting equipment on stands at stage level. (e.g. ‘We’re just focussing the dips now’)
3) Low lighting intensity when cross fading between two higher states – ‘there’s a dip between these two states’.
4) Transparent lacquer for colouring lamp bulbs – known as ‘Lamp Dip’.

DIRECT CURRENT
Electric current that flows in one direction only (e.g. from a battery). Abbreviated to DC. See also ALTERNATING CURRENT.

DISCHARGE LAMP
A high-powered source of light produced by means of an electrical discharge between two electrodes. An arc light, for example uses a discharge between two carbon rods which are manually or automatically fed together as they are burnt up. The use of this type of lighting is restricted to non-dimming applications such as followspots and projection, where dimming is achieved by mechanical means. Many of the new generation of moving lights use discharge lamps, dichroic filters and mechanical dimming shutters.
See BALLAST, CSI, CID, MSR, HMI, HTI, Xenon, MBI.

DISCONNECT
(US) Also known as a COMPANY SWITCH, this is a large capacity power connection point on/near the stage which touring companies can use to connect their equipment.

DISSOLVE UNIT
Interface connected between two or more slide projectors and a tape player. Synchronisation signals recorded onto the tape are detected by the dissolve unit and fade up the lamp in one slide projector while changing the slide in the other, and then vice versa, producing a dipless crossfade between the two images.

DISTRIBUTION BOARD
System of interconnected fuse carriers and cabling that routes an incoming power supply to a number of different outputs. Known colloquially as DISTRO.

DISTRO / POWER DISTRO
See DISTRIBUTION BOARD.

DMX512
See MULTIPLEXED (MUX) SIGNAL.

DMX512-A
See MULTIPLEXED SIGNAL.

DOME
1) (Aus) Follow spot location usually at rear of the upper gallery. Sometimes referred to as BIOBOX, where the control booth and followspot position are the same. 2) (Aus) A Followspot in any location (from the above).

DOME OP
Australian term for the followspot operator. See DOME.
Submitted by Mac Calder

DONUT
A metal plate with a hole in the middle inserted in the colour runners of a lantern to sharpen focus (in the case of a profile) or reduce spill.

DOUGHNUT
See DONUT.

DOWNLIGHT
A light from directly above the acting area.

DOWNSTAGE
1) The part of the stage nearest to the audience (the lowest part of a raked stage). [See Diagram]
2) A movement towards the audience (in a proscenium theatre).
Stage layout diagram

DOWSER (UK) / DOUSER (US)
A metal flag used in larger followspots and projection equipment to cut off the light beam without cutting off the electrical supply. Discharge lamps cannot be dimmed, so this is the only way of stopping light. Discharge lamps need a period of cooling down when they are turned off before they can be turned on again, so they should not be switched off if needed again within about two hours.
See also DIMMING SHUTTER.

DRESS LIGHTING
Providing a low level of lights to an open stage while the audience enter the house up until the performance starts. Also known as PRESET.

DRESS REHEARSAL
A full rehearsal, with all technical elements brought together. The performance as it will be ‘on the night’.

DRIFT WIRE
A length of suspension wire of standard length with eyelets at each end between the counterweight bar and the top of the scenic piece flown from it.

DRY ICE
Frozen solid carbon dioxide (CO2) at a temperature of -78.5° centigrade which produces clouds of steam-loaded CO2 gas forming a low-lying mist or fog when dropped into boiling water. Although non-toxic, caution is required in the storage and handling of dry ice because of its extreme cold. Water is boiled in a large tank offstage, into which the dry ice is lowered in a basket. Fans and ducts then direct the gas onto the stage. Dry ice does not support life, so care should be taken that small animals, actors etc.are not below the level of the dry ice for more than a few seconds.
See also LOW SMOKE.

E.R.S.
(ERS) Ellipsoidal Reflector Spotlight (US)

EARTH SPIKE
Copper rod inserted into the ground to maintain earth continuity (especially when using generators etc.)

EARTHING
Electrical safety requirement that metal parts of electrical equipment are connected to a common earth or ground point so that in the event of a fault, excess current can be carried away, causing the fuse to blow. Known in the USA as Ground.

EDISON PLUG
Standard domestic power connector in the USA – a plastic body with two parallel metal contacts.

EFFECTS PROJECTOR
Lantern used to project the image from a rotating glass effects disc. Used with an objective lens to produce the desired size of image. Commonly used discs are clouds, flames and rain.

EFFECTS, LIGHTING
Animation Disc: A slotted or perforated metal disc which rotates in front of a lantern to provide ‘movement’ in the light. Most effective when used in front of a profile carrying a gobo.
Effect Disc: A painted glass disc rotating in front of an effects projector with an objective lens to focus the image (eg Flames, Rain, Snow).
Flicker Flame: Irregularly slotted rotating metal disc through which light is shone onto a prism-type piece of glass which scatters the beam of light and adds the ‘dancing’ effect of firelight to a scene.
Gobo Rotator: Motorised device inserted into the gate of a profile lantern that can be remotely controlled to rotate a gobo, usually with variable speed and direction.
KK Wheel: Slotted metal disc which rotates in front of a lantern to break up the light and provide movement. (Flicker Wheel)
Lightning: Created through the use of either strobe sources or photoflood lamps.
Tubular Wave Ripple: Horizontal linear lamp around which a slotted cylinder is rotated providing a rising light (as reflected from water onto the side of a ship).
See also Effects,Sound, pyrotechnics, smoke.

EGGS
Slang term used for Strand Pattern 123′s, due to their shape.
Strand Archive

ELECTRIC
In the US, LX bars are ELECTRICs bars. LX1 in the UK (first bar upstage of the proscenium arch) is FIRST ELECTRIC in the US.

ELECTRICS
See LX.

ELEVATION
A working drawing usually drawn to scale, showing the side view of a set or lighting rig. See PLAN.
In the US, the term ‘elevation’ refers to a Front elevation. A Rear elevation shows backs of scenic elements. A side view of a set is known as a ‘section’.

ELLIPSOIDAL
A profile lantern with an elliptical reflector and at least one lens. Referred to as a LEKO.

EMF
Abbreviation for Electromotive Force, or VOLTAGE.

END ON
Traditional audience seating layout where the audience is looking at the stage from the same direction. This seating layout is that of a Proscenium Arch theatre. See also THRUST, IN THE ROUND, TRAVERSE.

EQUITY LIGHT
See GHOST LIGHT.
More on Ghost Light

ER / E.R.
(US) Short for Ellipsoidal Reflector – type of fixed beam profile lantern common in the US. Also known as ERS / E.R.S. See also LEKO.

ERF / E.R.F.
(US) Short for Ellipsoidal Reflector Floodlight. See also ERS.

ERS / E.R.S.
(US) Short for Ellipsoidal Reflector Spot. See ER, also ERF.

ESTA
(US) Entertainment Services and Technology Association. See PLASA for the UK equivalent.
ESTA website

ETC
(Manufacturer) US/UK based manufacturer of lanterns and lighting control equipment.
ETC website

ETHERNET
Computer networking protocol which is installed on many new lighting desks, to allow networking between the main desk, dimmers, and remote desks around the theatre.

EXCITER
1) See ENHANCER.
2) Exciter Lamp – the lamp in a film projector that shines through the optical soundtrack and enables it to be read by a light sensor.

EXIT SIGN
Usually illuminated sign, of standard size, which should always be visible, showing an audience member and the company the nearest exit.New legislation in Europe means that the word ‘EXIT’ has been removed from these signs to be replaced by ‘Running Man’, known more politically correctly as ‘Person moving purposefully’.

EXPRESSIONISM
Theatre design and performance style which places greater value on emotion than realism. The trademark Expressionist effects were often achieved through distortion.

F.B.O.
Abbreviation for Fade to Blackout.

FADE
A fade is an increase, diminishment or change in lighting or sound level.

FADE TIMES
On computerised memory lighting control desks, a lighting fade can have two times – an up fade and a down fade. The Up fade time refers to the time it takes dimmer levels to rise to their new positions. The Down fade time refers to the time for dimmer levels falling to their new positions.
More about Fade Times

FADER
A vertical slider which is used to remotely set the level of a lighting or sound channel.

FAR CYC
(US) Lighting instrument used to light cycloramas or drops (see also CYC FLOOD).

FEED
A power supply to a piece of equipment or installation is termed a ‘feed’. Sound equipment and sensitive computer equipment should have a clean feed – that is, a supply that is free from interference from other equipment.
A signal from one system to another is also known as a feed (for example, an audio signal from the FOH desk to a TV company videoing a concert is known as a feed.)

FEEDER
In the US, a main power cable to an installation is known as a feeder.

FESTOON
1) See Swag
2) Describes tabs which adopt a sculpted shape.
3) A length of cable incorporating a number of lamp holders used for outdoor party lighting etc. Available in multi-circuit form so that the lamps can be ‘chased’.

FIBRE FRAME
A colour frame made from heat resistant fibres, which doesn’t get as hot to the touch as a standard metal frame.

FIBRE OPTICS
A method of directing light down a very thin glass fibre. Fibre Optics are used mostly in communication, but find theatre applications in star cloths which are black backcloths with the ends of optical fibres poked through, to create a mass of pin pricks of light. A large bundle or harness of fibres may be fed from one light source, sometimes with a motorised colour or flicker wheel.
New technology enables digital sound signals to be sent down optical fibres, replacing heavy and expensive multicore cables.

FIELD
Refers to the spread of light intensity across a beam. Most profile lanterns have an adjustable field. A Flat field has an even distribution, a peak field has a ‘hot spot’ in the centre of the beam. A flat field is essential when using gobos. See Profile.

FILL LIGHT
(especially TV and Film lighting) Light which fills the shadows that key light creates.

FILTER
1) See Colour. 2) Electronic device to isolate and redirect specific frequencies in a speaker system.

FIRE EXTINGUISHER
Essential tools of the pyrotechnician’s trade ! In the UK, they used to be colour-coded according to content (Carbon Dioxide (Black), Water (Red), Foam (Cream), Halon Gas (Green) Powder (Blue)) but now, they’re all red with a small label saying what they are. Another great leap forward !.

FIRST ELECTRIC
(US) The first LX bar upstage of the proscenium arch. (Known in the UK as LX1).

FIT-UP
Initial assembly on stage of a production’s hardware, including hanging scenery, building trucks etc.

FIXTURE
A single moving light. Used instead of ‘lantern’ or ‘luminaire’ due to the added complexity of the equipment and the need for additional control connections.

FLAGGING
When focussing lighting, flagging means waving your hand in and out of the beam of a lantern/instrument in order to see where the beam is hitting on stage. Flagging is particularly useful in high ambient light levels. (e.g. ‘Can you flag that please ?’) Term probably originates from a FRENCH FLAG.

FLASH BOX
A small box containing the socket into which a pyro cartridge is plugged. Also known as a flash pod.

FLASH BUTTON
A push switch on a lighting desk which flashes selected channels / memories / submasters to full (100%) while pressed. Some Flash buttons on submasters can be set to latch (ie they stay on when pushed, until they are pushed again).
Sometimes known as a Bump Button.

FLASH COTTON
TO BE DEFINED

FLASH OUT / THROUGH
Method of checking whether lanterns are functioning properly by flashing them on one at a time. It is good practice to flash lanterns to 70%, rather than Full to preserve lamp life.

FLASH PAPER
TO BE DEFINED

FLIES
See FLY TOWER.

FLIGHTCASE / FLIGHT CASE
Metal framed wooden box on wheels with a removable lid used for transporting equipment between venues. Flightcases are very strong, and have reinforced corners and edges. Care should be taken when lifting flightcases as they can be very heavy.
The term comes from their original use in protecting delicate equipment when being loaded into air transport and being both very strong and relatively lightweight.
Additional information by Chris Higgs

FLOATS
Early form of footlights using burning wicks floating in oil across the front of the stage. Now applies to anything rigged on the front edge of the stage (eg Float microphones, Uplights / footlights etc.)

FLOOD
1) A lensless lantern that produces a broad non-variable spread of light. Floods are used in battens, or singly to light cycloramas or large areas of the stage.
See also CYC FLOOD.
2) To increase the beam angle of a Fresnel or PC by moving the lamp and reflector towards the lens. ‘Flood that a bit, please!’. The opposite movement is called Spotting.
Types of lantern

FLOORCANS
A PARCAN with an extra trunnion arm / yoke, and often a short nose, which is designed to sit on the floor.

FLOORPOCKET / FLOOR POCKET
(US) A electrical socket mounted under a flap in the stage floor (UK equivalent is DIP).

FLUORESCENCE
The property of some materials to glow when subjected to light. This normally refers to ultraviolet light, although blue visible light (along with many other colours) can cause fluorescence. The materials degrade the UV wavelengths into longer and therefore visible reflected rays. See also Phosphorescence.

FLY BARS
The metal bars to which scenery and lanterns are attached for flying above the stage.

FLYING PIG SYSTEMS
(Manufacturer) Makers of the Wholehog / Hog range of lighting control desks.
Flying Pig Systems website

FOCAL LENGTH*
TO BE DEFINED.

FOCUS
1) The session when all the lanterns in the rig are angled in the correct direction, with the correct beam size. 2) Description of how sharply defined a light beam is (‘give that profile a sharp focus’) 3) Control on projection equipment used to change the focus.

FOCUS CHART
Documentation produced by the lighting designer which shows graphically the exact focus of a particular lantern in the rig. Essential for long-running shows where the crew can use it as a reference when replacing lanterns or checking focus after cleaning etc. The charts can also be used to do a ‘rough’ focus before a lighting designer arrives at the venue. Touring shows sometimes use a floorcloth marked out with focus information to aid speedy focussing in a new venue.

FOCUS POINT
Function on some computerised lighting desks which allows the operator to specify a place on the stage to which moving lights can be made to move on cue. Once defined, the focus point can easily be recalled and used in multiple cues. If the location of that item is moved (e.g. the chair is moved to the right) all moving lights will automatically focus on the new location.

FOCUS SPOT
Term for both Fresnel and PC type lanterns with adjustable beam size.

FOCUSING
The process of adjusting the direction and beam size of lanterns. Does not necessarily result in a ‘sharply focused’ image.

FOG
See SMOKE MACHINE

FOG MACHINE
See SMOKE MACHINE.

FOH
See FRONT OF HOUSE.

FOLLOW-ON CUE / FOLLOW CUE
A cue that happens so soon after a previous cue, that it doesn’t need to be cued separately. The follow-on can be taken by the operator once a previous cue is complete, or a lighting or sound cue can be programmed to happen a specific time after a previous cue. Fly follow-on cues are often taken as soon as the operator has completed a previous cue. Often abbreviated to F/O.

FOLLOWSPOT / FOLLOW SPOT
Usually, a powerful profile lantern usually fitted with its own dimmer, iris, colour magazine and shutters mounted in or above the auditorium, used with an operator so that the light beam can be moved around the stage to follow an actor. Sometimes a beam light or other lantern may be used in the same way.
Powerful followspots use discharge lamps which cannot be dimmed, so these followspots have mechanical dimming shutters to dim the light output.
See LIMES, PICK-UP.

FOOT
1) The action of bracing the bottom of a ladder while a colleague climbs it (e.g. ‘Can you foot this for me please? I’ll only be a couple of minutes’).
2) Holding the bottom edge of a flat with your foot while a colleague raises the top of it to a vertical position.

FOOTLIGHTS
A compartmentalised batten sometimes recessed into the front edge of the stage, used to neutralise shadows cast by overhead lighting. Modern lighting equipment renders footlights virtually obsolete except for period/special effects.

FRENCH FLAG
Film/Video term. A card or metal panel fitted to an adjustable arm used to stop unwanted light from directly entering the lens of a camera.

FRESNEL
(pronounced ‘Fre-nell’) A type of lantern which produces an even, soft-edged beam of light through a Fresnel lens. The lens is a series of stepped concentric circles on the front and pebbled on the back and is named after its French inventor, Augustin Jean Fresnel (1788-1827). He developed the lens for French lighthouses so that they could be seen further out to sea and could achieve a longer focal length with a lot less glass than a standard plano-convex lens.
Types of lantern

FRONT OF HOUSE (FOH)
1) Every part of the theatre in front of the proscenium arch. Includes foyer areas open to the general public.
2) All lanterns which are on the audience side of the proscenium and are focussed towards the stage.
The backstage areas of the theatre are known as Rear of House (ROH).

FROST
A diffusing filter used to soften the edges of a light beam. Frosts are commonly used in profiles in front of house positions to achieve the same beam edge quality in all lanterns. Different strengths of diffusion frost are available from many colour filter manufacturers. See also SILK.

FTP
1) See also HIGHEST TAKES PRECEDENCE (HTP) and LATEST TAKES PRECEDENCE (LTP).
2) File Transfer Protocol – a method of transferring files across the internet.

FULL UP
A bright lighting state with general cover lanterns at ‘full’ (100%) intensity. See also FULL UP FINISH.

FULL UP FINISH (FUF)
A shorthand note for manual desk lighting operators to bring all relevant dimmers to full for the end of a song / finale of a show to ‘draw the applause’. Still applies for the snap build on the last beat of a song.

FUSE
Protective device for electrical equipment (E.g. dimmers). The fuse link will melt when excess current flows, preventing damage to people or equipment. Every piece of electrical equipment has at least one fuse in its associated circuit.

FUZZ LIGHT
A lamp with a revolving mirror and a coloured plastic dome. Gives a ‘police light’ effect. Usually 12 Volt or 240 Volt operation.

GAFFA TAPE
Ubiquitous sticky cloth tape. Most common widths are .5′ for marking out areas and 2′ (usually black) for everything else. Used for temporarily securing almost anything. Should not be used on coiled cables or equipment. Originally known as Gaffer’s Tape, from the Gaffer (Master Electrician) on a film set. See PVC Tape.
101 Uses for Gaffa Tape

GALAXY
(Trade Name) Large computerised memory lighting desk. Previously manufactured by Rank Strand (now Strand Lighting)
Strand Lighting website
Strand Archive

GAM
(Manufacturer) USA based manufacturer of lighting gels, gobos and accessories. GAM stands for Great American Market. See COLOUR FILTER, GOBO.
GAM website

GATE
1) The point of focus in a profile spot where the shutters are positioned and where an iris or gobo can be inserted.
2) A single base section of a folding rostrum system.
3) See NOISE GATE.

GAUZE
Cloth with a relatively coarse weave. Used unpainted to diffuse a scene played behind it. When painted, a gauze is opaque when lit obliquely from the front and becomes transparent when the scene behind it is lit . Many different types of gauze are available;
Sharkstooth gauze is the most effective for transformations, because it is the most opaque.
Vision gauze is used for diffusing a scene and for supporting cut cloths.
Also known as a Scrim.

GEL or Gelatine
See COLOUR FILTER.

GEMINI
(Trade Name) Medium size computerised memory lighting desk with 180 channels. Previously manufactured by Rank Strand (now Strand Lighting)
Strand Lighting website
Strand Archive

GENERAL COVER
Those lanterns in a rig which are set aside purely to light the acting areas. The stage is normally split into a number of areas for this purpose, which can then be isolated or blended together as required by the director. See Special.

GENERIC
Standard stage lighting instruments, rather than moving lights or other effects. (e.g. ‘There are 40 instruments in the rig – 20 moving lights and 20 generics’).

GENIE
(Trade Name) A range of mobile access platforms or lifting devices with either hand-cranked or compressed air lifting mechanisms.
Genie Industries website

GERB
See PYROTECHNICS.

GET-OUT
Moving an entire production out of the venue, and into either a large waste-disposal skip, or into transport. Usually preceded by the strike. (aka Load out or Bump out.)

GFI / G.F.I.
(US) Ground Fault Interruptor. See RCD.

GHOST LOAD
A lamp or group of lamps used to smooth out the waveform from electronic dimmers when using an inductive load(ballasts, transformers) rather than a resistive load (lamps). Also known as a Load Lamp.

GHOSTING
A method of determining the exact position of a followspot’s beam by faintly exposing it on a darker area of the stage or upon the drapes. Often done just before a ‘pick up’ so the operator can have the lantern aimed and ready. A more professional practice is to use sights to line up a followspot.
Submitted by Jayson Bowles

GHOSTLIGHT / GHOST LIGHT
(US) A light left burning overnight on stage to keep friendly spirits illuminated and unfriendly spirits at bay. Also believed to keep the theatrical muse in a ‘dark’ theatre, and to stop people tripping over bits of scenery when they come into the theatre in the morning.
Also refers to the light emitted by a lantern when a dimmer has not been ‘trimmed’ correctly, and is leaking.
Also known as the ‘Equity Light’. See link below for more information.
More information about Ghost Light

GLOVES
Used when lifting heavier lanterns or other equipment.

GLS
General Lighting Service. Lamps designed for general everyday use.

GOBO
A thin metal plate etched to produce a design which can then be projected by a profile spotlight. There are hundreds of gobo designs available – common examples are breakup (foliage), windows and scenic (neon signs, city scapes etc.). The image can be used soft focus to add texture, rather than a defined image. A number of composite gobos in different coloured lanterns can, with careful focusing, produce a coloured image (e.g. a stained glass window). Greater detail can be achieved using a glass gobo, which consists of a thin layer of aluminium etched onto glass.
There are a few possible origins for the word GOBO.
1) It came from the early days of Hollywood. When the Director of Photography wanted daylight excluded from some area of the set, he’d say ‘GO BlackOut’. Loads of people would run around putting black material between the sun and the set.
2) It stands for Graphical Optical BlackOut.
3) It’s short for Go-Between, as the gobo goes between the lamp and the lens.
4) It’s short of GO Before Objective (i.e. it goes before the Objective lens).
Material from 1967 uses the word ‘MASK’, and no mention is made of ‘GOBO’, so we can assume the word wasn’t in widespread use then. In the US TV/Film industry, a Gobo is a piece of material used to mask or block light, placed in front of a lantern (also known as a SHADOW MASK) and a Cookie (short for Cucaloris(from the Greek kukaloris: the breaking up of light)) is the same as a UK Gobo. PATTERN and TEMPLATE can also refer to a gobo in some areas.
In the film industry, the word gobo can be used as a verb (e.g. ‘We need to gobo off that light so the camera doesn’t see it’).

GOBO HOLDER
A metal plate designed to hold a gobo of a particular size in a lantern of a particular type.

GOBO ROTATOR
See EFFECTS.

GOING DARK
1) See DARK.
2) Warning to people on stage that the lights are about to be switched off. Normally said during lighting plotting sessions or technical rehearsals.

GRAND MASTER
See MASTER.

GRELCO
Brand name for a 2 way 5A or 15A electrical splitter. Another name is SNAPPER (another brand name) or in the US ‘TWOFER’. Sometimes shortened to GRELLY. A three way splitter is known as a TRELLY (or THREEFER in the US). These splitters are always wired parallel (voltage equal, current shared). See ‘Series Splitter’ which enables (for example) two 115V lamps to be connected to a 230V supply.

GROUND PLAN
Scaled plan showing the exact position (seen from above) of all items standing on the stage floor and indicating the position of items suspended above. Typical scales are 1:24 (.5′ to 1 foot) or, metrically 1:25 (1cm to .25m). Venues have a base plan showing proscenium, walls, seating etc on which individual set and lighting plans can be drawn.

GROUNDROW
1) A long piece of scenery positioned at the base of a backcloth usually to mask the very bottom of a cloth or lanterns lighting a cloth.
2) Compartmentalised floodlight battens at floor level used to light the bottom of skycloths etc.

GROUP
A subdivision, permanent or optional, of a lighting board control preset, or a sound desk.

HALOGEN CYCLE
Chemical process occurring in Tungsten Halogen lamps which makes them possible. During the lamps life, Tungsten evaporates from the filament, and would normally deposit itself on the glass wall of a Tungsten lamp, causing it to blacken, and causing the output of the lamp to reduce until it finally blew. In a Tungsten Halogen lamp, the Tungsten combines with the Halogen gas elements present in the lamp envelope and is re-deposited back onto the filament. This process needs a very high temperature to operate, so Tungsten Halogen lamps are able to be a lot smaller, and run a lot hotter, than their Tungsten equivalents. See also Tungsten Halogen.

HANG
The ‘hang’ is the American equivalent of the lighting rigging session in the UK – the time when the lighting equipment is rigged.

HARMONY
(Trade Name) Range of 1000W lanterns produced by Rank Strand (now Strand Lighting) in the UK.
Strand Lighting website
Strand Archive

HAZER
See SMOKE MACHINE.

HEADS
The top lantern on a lighting boom. See SHINS and MIDS.

HEADS ON STAGE
A shouted warning (often just ‘Heads !’) for staff to be aware of activity above them. Also used when an object is being dropped from above.

HEADSET
1) General term for theatre communication equipment.
2) A headphone and microphone combination used in such communications systems with a beltpack.
See also CANS.

HEATSHIELD
Made by Rosco, Heat Shield is a special clear gel which when placed between a lamp and a coloured gel, dissipates a large amount of heat to give the gel a longer life. There must be an air gap between the Heat Shield and the gel, or it will not be effective.
Rosco website

HIGH HAT
See TOP HAT.

HIGHEST TAKES PRECEDENCE*
Abbreviated to HTP, this is the standard by which some lighting desks operate.
If there is more than one control on the desk affecting a particular channel, then the highest level of the controls will take priority and affect the output of the desk and the dimmers.
This system is universal on manual lighting desks, but there are problems with the control of moving lights, scrollers etc.
See LATEST TAKES PRECEDENCE.

HMI (Hydragyrum Medium arc-length Iodide)
A mercury-halide discharge lamp with a colour temperature of 5600K (daylight).

HOOK CLAMP
A clamp with a wing bolt for hanging a lantern on a horizontal lighting bar.
Introduced in the UK in 1959 by Strand, replacing the 2-bolt and 2-nut L Clamp.
See SAFETY CHAIN and BOOM ARM.

HOOK UP
A Hook Up is paperwork generated by the Lighting Designer for a show. It lists connections or layouts between number systems. For example, a Channel Hook Up lists the channel numbers used on the lighting plan alongside the dimmer numbers into which they’re connected, and a brief text description of that channels function.

HOT SPOT
The brightest part of the beam from a lantern, usually showing the centre. Profile lanterns have a Field control which enables a beam to be flattened so it has no hot spot.

HOUSE LIGHTS
The auditorium lighting which is commonly faded out when the performance starts.

HOWIE BATTEN
(After Howard Eaton) This is a two circuit (two colour) 120V per circuit MR16 batten developed by Howard for lighting cloths at close proximity. A row of these hung above a cloth allow you to light the cloth where there is little space. They have also become popular as footlights.
Howard Eaton Lighting Ltd. website

HTI
See DISCHARGE LAMP.

HTP
See HIGHEST TAKES PRECEDENCE.

IEC / I.E.C.
International Electrotechnical Commission. The UK mains inlet connector / ‘kettle lead’ is known as an IEC LEAD.
IEC website

IMPEDANCE
A term for the electrical resistance found in a/c circuits. Affects the ability of a cable to transmit low level (e.g. sound) signals over a long distance. Measured in Ohms. Speakers are rated according to power handling capabilities (Watts, W) and impedance (Ohms).

IN THE ROUND
Theatre in the Round is a form of audience seating layout where the acting area is enclosed on all sides by seating. There are often a number of entrances through the seating. Special consideration needs to be given to onstage furniture and scenery as audience sightlines can easily be blocked.
Stage managers and directors often use the idea of a clock face to describe actor positions on stage (e.g. the aisle nearest the technical point is described as the 12 O’clock position, with other aisles described as 3, 6 and 9 O’clock.)
See also THRUST, END ON, TRAVERSE.

INCANDESCENT
Light source consisting of a metal filament (Tungsten) which glows white hot when current is passed through. See also Discharge Lamp.
How do Incandescent Light Bulbs Work?

INDEPENDENT
1) An electrical power supply that is totally separate from the stage lighting control. Used for testing lanterns prior to connection to the lighting system and also for powering non-lighting equipment on stage and working lights. See NON DIM.
2) A channel within the stage lighting control which has been temporarily switched to become independent from the rest of the channels which remain under the control of the operator.

INFRA-RED
Invisible part of the electromagnetic spectrum with a longer wavelength than visible light. Infra-red remote controls are used for lighting desks and practicals. An infra-red-sensitive CCTV camera can pick up body heat activity even in a ‘blackout’.

INHIBIT
A way of taking control of a rogue lantern (or lanterns) at the lighting desk during the operation of a show and removing them from any further lighting states, until the inhibit is removed. Can also be used for removing the front of house lighting from a curtain call state. See also SUBMASTER.

INHIBITIVE SUBMASTER
See SUBMASTER.

INSERT
1) An additional route into a sound desk.
2) An extra lighting state added into the sequence later. See POINT CUE.

INSTALLATION
1) An electrical system in a particular building (e.g. ‘the stage lighting installation was tested last year’)
2) A piece of art designed to transform a particular room or building into something other than a room in an art gallery. Installations often use complex audio-visual equipment and can be intensely immersive experiences. As with all art, they can also be rubbish.

INSTRUMENT
(US) Same as a LANTERN or LUMINAIRE in the UK/Europe.

INTELLIGENT LIGHT
See MOVING LIGHT.

INTERNALLY WIRED BAR (IWB)
A Scaffolding bar (aluminium) which has a number of sockets (usually 15A) positioned along its length, the wiring for which is contained within the bar. See SIX LAMP BAR.

IRIS
Adjustable aperture which, when placed in the gate of a profile lantern, varies the size of a beam of light. Originally, iris diaphragm.
Most followspots have an iris permanently installed.

JONES PLUG / JONES SOCKET
Type of multipin connector used on some lighting desks for analogue outputs.
CINCH website

JUMPER
An adaptor from one type of electrical connector to another. For example, a 13 – 15A jumper has a 13A plug and a 15A socket at either end of a short cable. Also applicable to sound cables.

K
Lighting Industry Forum code which identifies the (original) recommended usage of different lamp types. K coded lamps are for use in general purpose flood lighting, and have a colour temperature of 2850°K. See also CP, A1, T, P2.

KELVIN
See COLOUR TEMPERATURE.

KEY LIGHT
(Esp. TV & Film lighting) The dominant light source/direction in a naturalistic lighting state. In a sunny drawing room, the key light would be through the window, for a naturalistic exterior scene the direction of the key light could change as the sun progressed across the sky. See FILL LIGHT.

KICKER LIGHT
Lanterns placed to the side of the actor to maximise the sculptural quality of the light are sometimes known as KICKERS.

KILL
To switch off (a light/sound effect); to strike/remove (a prop).

KILOWATT
1 kilowatt (1kW) is equal to 1000 Watts. The WATT is a measure of electrical power.

KIT
1) General name for equipment, especially nice shiny equipment, leading to the comment ‘That’s a nice bit of kit’
2) Short for Drum kit.

KK WHEEL
A type of animation disk which fits into the colour runners at the front of a lantern which rotates and breaks up the light beam to make it appear to be moving. Best used on a profile lantern containing a gobo. A KK Wheel is known in the US as LOBSTERSCOPE.

KVA
Kilo-Volt Amps. Unit of electrical power.

LADDER
Non-climbable structure in the shape of a ladder from which lanterns can be hung in a vertical ‘stack’.

LAMP
A light bulb is used in domestic situations (i.e. in the home). In the industry, we only use LAMPS. As the saying goes, ‘Bulbs is what you put in the ground’. Example usage: ‘The lamp in the DSC fresnel has blown’. In the TV/Film world, a lamp is called a BUBBLE.

LAMP TRAY
Lower section of the body of a theatre lantern on which the lamp holder is mounted. Some lamp trays are hinged, some are removable from the rest of the body. Modern safety legislation (UK) requires that the lamp tray cannot be opened until power is disconnected.

LAMPY
Theatre / Rock & Roll lighting technician. Distinct from a ‘Techie’ who may also be a carpenter or stage crew member. A lampy only concerns him/herself with lighting. See also JAFIE, TECHIE and NOISE BOY.

LANTERN
1) General term for unit of lighting equipment including spotlight, flood etc. Term now being replaced by the internationally recognised ‘luminaire’ (esp. Europe) or ‘instrument’ in the US.
See also FIXTURE.
2) Glazed section of roof usually in haystack form over the fly tower that automatically opens in the case of fire. An updraught is created which inhibits fire from spreading quickly into the auditorium, and prevents build-up of smoke at stage level.

LASER
Acronym of Light Amplification by Stimulated Emission of Radiation. A very high energy beam of light that remains virtually parallel throughout its length. Visible in the air only when a haze of smoke or dust is introduced. Great care is required when using lasers as this energy can cause permanent damage to the retina of the eye.
How Lasers Work

LATEST TAKES PRECEDENCE*
Abbreviated to LTP, this is a standard by which some lighting desks operate.
If there is more than one control on the desk affecting a particular channel, then the latest control to operate will be the one to affect the output on stage.
This system is used on desks with moving light functionality
See also HIGHEST TAKES PRECEDENCE.

LCL
Abbreviation for Light Centre Length. This measurement (in mm) is the distance between the top of the lamp base and the optical centre of the filament. This measurement is critical as it ensures that for a particular lantern, the filament is at exactly the correct position for maximum light output and efficiency. Many different lamp types exist, but there are far fewer lamp-base types, meaning it’s possible to insert the wrong lamp into a lantern very easily, resulting in poor output and efficiency.
See also MOL.

LD / L.D.
Lighting Designer.

LE MAITRE
(Manufacturer) UK based manufacturer of pyrotechnic devices (Pyroflash brand name), smoke machines and other theatre effects
Le Maitre website

LECTRIFLEX
Multipin connector for carrying multiple lighting circuits down a multicore cable. See also SOCAPEX.

LED / L.E.D.
Light Emitting Diode. LED technology is becoming extremely useful in the areas of architectural lighting and video walls. LED light sources are becoming brighter and cheaper. They are extremely efficient, and give off very little heat, making them ideal for display or architectural work. LED video walls are in use all over the world – they are more efficient and lighter in weight than projection alternatives.
The LED Museum
How LEDs work

LEE
(Manufacturer) UK based manufacturer of lighting gels. See COLOUR FILTER.
Lee Filters website

LEKO
A type of ellipsoidal profile spot, much used in the USA. Contraction of the original manufacturers names.
Types of lantern

LENS
Optical glass with one or both sides curved, the purpose of which is to direct light by concentrating or dispersing light beams.

LIGHT
TO BE DEFINED
How Light Works

LIGHT BOARD
See BOARD.

LIGHT CURTAIN
A lighting effect which, when an area is diffused with smoke, produces a wall of light. Produced (usually) by a batten of low voltage PAR lamps wired in series.
Automated versions are available which have colour changers built-in and are able to tilt up and down. The original Light Curtain designed by Josef Svoboda is still made by ADB. (See SVOBODA, DIGITAL LIGHT CURTAIN)

LIGHT JOCKEY or LJ
Danish slang for Lighting Designer.
Submitted by Erling Larsen

LIGHTING PLAN
A scale drawing detailing the exact location of each lantern used in a production and any other pertinent information (E.g. its dimmer number, focus position and colour number). Often drawn from the theatres’ groundplan.

LIGHTING PLOT
The process of recording information about each lighting state either onto paper or into the memory of a computerised lighting board for subsequent playback. (in USA, this term is used for a lighting plan and a lights session is when lighting states are set up.)

LIGHTING STATE
The format of lighting used at a particular point in the production; a lighting ‘picture’. A lighting cue is given by the stage manager which initiates the change from one lighting state to the next.

LIGHTING STENCIL
Plastic stencil containing a range of scale symbols for current lighting equipment. Greatly facilitates the drawing of lighting plans.

LIGHTJOCKEY
Club / DJ control and visualisation software by Martin.
Martin website

LIMELIGHT
An obsolete source of intensely bright light, most recently used in followspots.Derived from a burning jet of oxygen and hydrogen impinging on a rotatable cylinder of lime.
See LIMES.

LIMES
Followspots and their operators. This term is still in everyday use, although limelight is not. See also PICK-UP.

LINK
See POINT CUE.

LINNEBACH PROJECTOR
Optically simple lensless system for projecting a shape from a gel or glass slide etc. onto a set or cloth. The slide is placed in the front runners of the projector which is a floodlight (with a point source lamp, and no reflector). Often used for shadow effects or simple scenic projection. The projector was developed in Germany by Adolphe Linnebach (1876-1963) in 1916 at the Court Theatre, Dresden. In order to get a sharp image, the lamp filament should be as small and as bright as possible, with adjustment to move it towards and away from the slide. A high intensity low voltage lamp is often used for this purpose.
See also OLIVETTE.

LOAD
1) The electrical power rating, in Watts, of the equipment connected to a particular lighting dimmer. 2) The equipment connected to a dimmer.

LOAD LAMP
See GHOST LOAD.

LOBSTERSCOPE
A mechanical device that reproduces the flashing ‘motion-freezing’ effect of a strobe. See also KK WHEEL.

LOW SMOKE
Smoke that has been chilled as soon as it comes out of the smoke machine. This causes the smoke to lay close to the floor. Use fast dispersing smoke for this effect because when the smoke heats up in the air, it will rise.
Low Smoke is much safer to work with than DRY ICE, which produces a longer-lasting effect but is more expensive.
See also CRYOGENICS, DRY ICE.

LOW VOLTAGE
Lower voltage lamps give more intense light than mains voltage lamps of the same wattage.

LTP
See LATEST TAKES PRECEDENCE.

LUMEN / LUMENS
A measure of light output from a source. The brightness of video projectors is stated in Lumens.
See also LUX.
What Lumen rating projector should I use?

LUMINAIRE
The international term for lighting equipment. Not restricted to theatre lighting.

LUX
A measure of the level of illumination on a surface (1 lumen spread over 1 metre).

LX
Short for Electrics. The department in the theatre responsible for stage lighting and sometimes sound and maintenance of the building’s electrical equipment.

LX TAPE
See PVC TAPE.

MAC
A range of professional moving lights made by Martin in Denmark.
Martin website

MAGIC SHEET
See CHEAT SHEET.

MAINTAINED LIGHTING
See Secondary lighting.

MANUAL DESK
A lighting desk where the interface between operator and dimmer is a fader, rather than a computer. Many modern manual desks have some memory facilities built in, but there are still a large number of venues with solely manual systems.

MAROON
An electrically detonated pyrotechnic device giving the effect of a loud explosion. Made from gunpowder encased in stout cardboard or string. Must be used within a metal bomb tank. Originally developed in the second half of the last century to simulate the sound of cannon. It was often used to call out the volunteer lifeboat crew in an emergency.

MASK
1) Form of theatre where actors faces are covered with masks.
2) Early word for GOBO.

MASTER
1) An overall control on a lighting or sound control board. The Grand Master takes precedence over all other controls. See Submaster.
2) An original (e.g. Master tape, master plan) which should be used only to make a copy from which to work.
3) A Department Head (e.g. Master Carpenter, Master Electrician).

MASTER ELECTRICIAN
See CHIEF ELECTRICIAN.

MAXXYZ
Moving Light console produced by Martin.
Martin website

MBI
Metal Halide discharge lamp. See also DISCHARGE LAMP.

MCB
Minature Circuit Breaker. Up to 63A (UK). See FUSE.

MCCB
Moulded Case Circuit Breaker (over 63A – UK). See FUSE.

MEATRACK
Wheeled rack for transporting a number of pre-rigged six-lamp bars or lanterns.

MEMORY BOARD
An electronic storage device which enables recording and subsequent ‘playback’ of lighting states.

MIDS
The middle lantern on a lighting boom. See SHINS and HEADS.

MIMIC
The VDU associated with most medium and large lighting desks has a detailed mimic of the level of all dimmers and other associated information.

MINIM
(Trade Name) Range of 300W lanterns produced by Rank Strand (now Strand Lighting) in the UK.
Strand Lighting website
Strand Archive

MINUETTE
(Trade Name) Range of 500W/650W lanterns produced by CCT in the UK.
CCT Lighting website

MIRROR BALL
A lighting effect popular in discos, ballrooms etc. A large plastic ball covered with small mirror pieces. When a spotlight (usually a PINSPOT) is focused onto the ball, specks of light are thrown around the room. Usually motorised to rotate.

ML
Short for MOVING LIGHTS.

MOGUL BASE*
A type of lamp base. More information coming soon…

MOL
Abbreviation for Maximum Overall Length. This measurement (in mm) is the length between the ceramic lamp bases at each end of a double ended (linear) lamp, such as that used in floods and some discharge lamps.
See also LCL.

MOLEFAY
(Trade Name) 8-lamp flood lantern used for washing large areas of stage with colour, or as an audience ‘blinder’ for a concert. Sometimes fitted with colour scrollers for maximum flexibility. Consists of 8 PAR 36 ACL (AirCraft Landing) lamps.

MONITOR
1) An onstage speaker which allows a performer to hear the output of the PA system, or other members of a band.
2) A video display screen (not normally able to receive broadcast TV pictures) used with a CCTV system or a computer.

MOON BOX
Lighting effect. A large shallow circular box with calico cloth on one face and low wattage lamps arranged on the back. Can be flown behind a gauze or thin cyclorama to give the effect of the moon rising.

MOVING HEAD
See MOVING LIGHT.

MOVING LIGHT
Remotely controllable ‘intelligent’ lighting instrument. Each instrument is capable of a massive variety of effects which are operated ‘live’ via a moving light control desk, or can be pre-programmed by a standard memory lighting desk. The instruments require a power supply and a data cable (normally carrying DMX512 signal from the control desk). There are broadly two types:
1) Moving Head: A luminaire is mounted on a moving yoke.
2) Moving Mirror: A stationary luminaire directs light onto a motorized mirror.
Both types have in common:

  • A discharge (non-dimmable) light source
  • A dimming shutter
  • Motorized rotating colour wheels. Some offer colour mixing using graduated red, green and blue wheels or prisms.
  • Profile versions have motorized gobo wheels with rotation.
  • Strobing effects and adjustable iris. Some also have shutters.
    The term ‘intelligent’ is used as the instrument has a processor chip and electronics built into it, not because it’s able to interpret the designer’s artistic intent! It can be incredibly frustrating trying to get moving lights to behave exactly as required in a dramatic situation. Musicals and live music performances are more forgiving.
    Moving Head lanterns are sometimes known as NODDING BUCKETS, Moving Mirrors are sometimes known as WIGGLIES or SCANNERS.

MOVING MIRROR
See MOVING LIGHT.

MR16
A 12 Volt lamp dichroic lamp commonly used in place of a Par 16 lamp in BIRDIES. See BIRDIE.

MSD
TO BE DEFINED

MSDS
Material Safety Data Sheet. Form available from manufacturers of, for example, smoke fluids. Lists any hazardous ingredients and other safety-related data about the product.

MSR
(Medium Source Rare earth) High efficiency discharge lamp with a high colour temperature (approx 5600°K). Provides around 50% more light output than a incandescent lamp of the same wattage.

MULTI
Short for MULTICORE.

MULTICORE
A flexible electrical cable composed of several well-insulated cores covered in a strong PVC or rubber covering. Enables a number of different circuits to be carried down one piece of cable. Both lighting and sound multicores are available. Sometimes known as a Multi or Snake.

MULTIPAIR CABLE
See MULTICORE.

MULTIPLEXED (MUX) SIGNAL
All modern lighting desks use this serial form of communication with dimmers. All the information from the desk is transmitted along a single pair of cables to the dimmer where a de-multiplexing unit (demux box) decodes the string of data and passes the correct piece of information to the correct dimmer.
The industry standard protocol (language/standard) for multiplexing is the digital USITT DMX512 (introduced in 1986, based on RS485 data protocol). However, new protocols are continually being added to keep up with more demanding equipment.
SMX is a communications protocol which enables digital dimmers to ‘report back’ to the desk on any faults (eg blown lamps).
RDM (Remote Device Management) is an emerging upgrade to DMX512 which will include bi-directional communication between controller and device.
DMX512-A (officially ANSI E1.11) is a new standard under development at ESTA which is backwards compatible with DMX512 but has stricter safety parameters and offers some upgrades of functionality.
Among the older protocols (pre DMX512) are D54 which uses a stream of analogue voltage levels and was the Strand standard, and AMX 192 (US Standard, introduced around 1975) which can control up to 192 channels and uses a 4-pin XLR connector. (AMX stands for Analogue Multiplex).
See also UNIVERSE.
USITT page about DMX512
DMX FAQ

NC / N.C. / N/C
1) (US) No Color (US equivalent of UK’s OPEN WHITE).
2) Not Connected (in a circuit diagram).

NEON
1) A type of discharge lighting generated by a high voltage across two oppositely charged electrodes at opposite ends of a long, thin glass tube filled with neon gas. As the electrical charge flows between the electrodes, electrons collide with neon atoms causing them to give off energy in the form of visible light. Different colours can be obtained by mixing other gases, or by using fluorescent coatings. Mostly used for advertising signs – the glass tube is bent to form letters.
2) A small mains voltage indicator lamp.

NEUTRAL DENSITY FILTER
(ND) Lighting filter which reduces the brightness/intensity of a light source without changing its colour value. Used extensively in TV/film for reducing the intensity of discharge lamps or natural light sources (e.g. windows). Rarely used in theatre as dimmers fulfil a similar function (although as incandescent lamps are dimmed, the colour temperature gets warmer).

NIETHAMMER
(Manufacturer) Brand of zoom profiles & followspots with halogen or HMI lamps. Very popular in Europe. Named after Emil Niethammer.
ADB website
Submitted by Andre Broucke

NON DIMS
Channels, usually controlled from the lighting desk which are switched, rather than dimmed. This enables motors, slide projectors, smoke machines etc to be controlled from the lighting desk.

OBIE LIGHT
Compact light fitting designed to mount just above a film/stills camera lens for two reasons: firstly to create a characteristic glint in the eye of the subject of the photograph/film (it’s known as the Eye Light), secondly to flatten out any lines/wrinkles in the face of the subject. The Obie Light is named after the actress Merle Oberon (known to friends as ‘Obie’). It was first used by her husband, cinematographer Lucien Ballard, in the 1940s to make lines and shadows disappear from her face which were due to scarring following a car accident.
The Obie Light is normally heavily diffused.

OFFSTAGE
1) A movement towards the nearest side of the stage from the centre. (e.g. ‘Focus that spot offstage a bit please’)
2) The area out of sight of the audience (e.g. ‘Get that donkey offstage !’)
Stage layout diagram

OHM
The unit of electrical resistance.

OLIVETTE
Lighting instrument using an incandescent lamp (usually mogul screw-base, 1000W). The lamp was usually mounted base-up, facing a large opening (the size of a full sheet of gel). Now used as a cyc flood, the instrument was originally designed for projecting painted glass images onto cycs. See also LINNEBACH PROJECTOR.
Submitted by Audrey Glickman

ONSTAGE
A movement towards the centre of the stage from the sides.
Stage layout diagram

OPEN WHITE
(o/w) Lighting with no colour filter. Known in the US as NC (no color).

OPTICAL FIBRE
See FIBRE OPTICS.

OUTRIGGER
An extendible leg to increase the stability of access equipment (eg Tallescope, Scaffold tower).

OVERLAY
(Followspot term) The wider of two followspot beams covering the same performer.
(i.e. lamp one in a pink ‘bust’ (head-to-shoulder) and lamp two in a blue full-body overlay (head-to-toe).
Submitted by Bert Morris.

P2
Lighting Industry Forum code which identifies the (original) recommended usage of different lamp types. P2 coded lamps are photofloods, and have a colour temperature of 3000°K. See also PHOTOFLOOD, CP, A1, T, K.

PAGE
1) See PAGING. 2) Some theatre announcement systems use the term ‘PAGE’ to mean making a call (e.g. ‘Can you page Simon to come to the fly floor’)
3) A way of increasing the functionality of a control on a lighting desk. For example, most computerised lighting desks with SUBMASTERS will allow you to store more than one lighting state in each submaster. Each group of submasters is given a page number which is used to select which set you want to use. See also SUBMASTER.

PAGEANT
(Obsolete) Brand name of a 1000W beamlight made by Strand Electric in the UK. Produced a near parallel beam and had a set of spill rings on the front to minimise glare.
Strand Archive – Pageant

PAIRING
Connecting more than one lantern to one power outlet via an adaptor or splitter, or more than one speaker to one amplifier channel.

PAN
1) A control on a mixing desk which allows the operator to position the channel’s output in the final stereo image (L – R).
2) A horizontal (side-side) movement of a camera or a moving light. Short for Panorama. See also TILT.

PAR
Short for Parabolic Aluminised Reflector lamp. A lamp containing a filament, reflector and lens in one sealed unit. Used in PARCANs to produce a high intensity narrow beam of light. Par lamps are available in many different sizes and powers. Par sizes available include 16, 36, 38, 56 and 64. (The number refers to the diameter of the lens, in eighths of an inch). The most common for theatre use are Par 64s rated at 1000W (1kW), although other wattages are available. 110V Par lamps are often used in large UK venues or for touring due to the increased light output. Because the current is greater, the lower voltage lamps have smaller thicker filaments which give a more focussed beam than the thinner 240V filaments.
In the film business, PAR lamps are known as ‘bird’s eyes’ after the alleged inventor Clarence Birdseye.

PAR BAR
See SIX LAMP BAR.

PARABOLIC REFLECTOR
See PAR.

PARALLEL
1) The folding frame that forms the base of a readily portable platform.
2) The opposite of SERIES when referring to wiring two loads into one outlet. The two loads share the available current, but are both given the same voltage.

PARCAN
Type of lantern which produces an intense beam of light, ideally suited to ‘punching’ through strong colours, or for special effect. The Parcan is literally a cylinder of metal (the ‘can’) within which sits the PAR lamp (PAR stands for Parabolic Aluminised Reflector) which consists of the bulb, a reflector and a lens in a sealed unit. The Parcan first appeared in the early 1970′s in the Rock concert industry due to the intensity of the beam, and the light weight and near indestructibility of the lantern. The lens of the lamp is either clear (which produces a narrow beam), frosted (medium) or stippled (wide).
See also PAR and FLOORCAN.
Types of lantern

PARNEL
Brand name for a wash light manufactured by ETC. It’s a cross between a soft-edged focussable Fresnel and a ETC Source Four PAR.
ETC website – PARnel

PATCH
1) (verb) The act of plugging a lantern into a dimmer (e.g. ‘Can you patch circuit 12 into dimmer 18 please’).
2) (noun) The system for connecting lanterns to dimmers (The Patch).
The term also applies to sound – a PATCH BAY is used to connect outboard equipment into the sound desk and to connect sound desk outputs to amplifiers, and amplifiers to speakers.

PATCH PANEL
A board consisting of rows of sockets into which plugs can be connected to route sound signals or power for lighting circuits. Some American systems use a Pin Plug patching system. See also PATCH.

PATCHING
1) To cross-connect lighting circuits around the stage area to a chosen dimmer. Connecting lanterns to dimmers.
2) Using a cross-connect panel which enables any stage lighting channels to the control desk to control any dimmer or group of dimmers. Some large lighting boards have the facility for soft patching – a totally electronic way of patching. Some Rock Desks have a pin patch which allows groups of dimmers to be allocated to a particular control channel. Also applies to routing of sound signals.

PATTERN
1) See GOBO.
2) See PATTERN NUMBER.

PATTERN NUMBER
Many older Strand lanterns are identified by their Patt. number (eg Patt.23 is a 500W profile). The numbers bear no direct relation to their size or type (although lanterns of a similar design may have similar Pattern numbers.) See http://www.strandarchive.co.uk for a complete listing.
Strand Archive website

PC
Originally short for plano-convex – the basic lans shape of many lanterns / projectors. Now short for Prism- or Pebble-convex: a type of lens with a pebbled flat surface which gives a slightly harder edge than a Fresnel, but not as hard as a Profile. PC refers to a lantern with a PC lens.
Types of lantern

PEBBLE SPOT
See PC.
Types of lantern

PEPPER’s GHOST
Optical illusion effect used to make a ghost appear on stage next to an actor. A sheet of glass is hung across the front of the stage so that the image of an actor standing in the orchestra pit appears to float on stage. First shown at the Royal Polytechnic Institution in London by J.H.Pepper on Christmas Eve, 1862. Following many subsequent events, Charles Dickens used it during readings of The Haunted Man. Several plays were written specially to use the effect around 1863, but the long-term future of the effect was limited by the fact that the ghost couldn’t speak. Peppers Ghost is now used to great effect in smaller scale applications like the Haunted Mansion in Disney theme parks.
More about Pepper’s Ghost

PERCENT
Dimmer levels are expressed as a percentage of the supply voltage. (100% = 230 – 240 Volts(UK)).

PERCHES
Lighting positions (often on platforms) at each side of the stage, immediately behind the proscenium.
Some theatres use the term for vertical boom positions in front of the proscenium in the house.

PHASES
Electricity is generated and supplied to large installations as three separate supplies, known as phases.
In the UK, the three supplies are colour-coded to ease identification. Each of the Red, Yellow and Blue phases are supplied down one cable to the building, but effectively give three separate supplies. Because there is a potential difference (voltage) of 415 volts between any two phases and earth/ground, care must be taken that pieces of equipment powered by different phases are not capable of being touched at the same time in case of a fault.

PHOENIX
A family of medium to large computerised lighting consoles manufactured by ADB. The desks use ISIS software running on an external PC-based processing unit which allows advanced networking possibilities.
ADB website

PHOSPHORESCENCE
The property of some materials that can store light energy and glow in the dark.

PHOTOFLOOD
A lamp used by photographers which gives a bright white light. Because it has a thin filament, it gives a good flash effect (eg lightning), but has a relatively short life, so should not be left on for any length of time.

PICK-UP
1) Device which, when attached to an acoustic musical instrument, converts sound vibrations into an electrical signal.
2) A way of describing the directional sensitivity of a microphone. An Omnidirectional microphone has equal pick-up from all around, a Cardoid microphone is more sensitive from the front, a Hypercardoid has very strong directionality from the front. A figure-of eight microphone picks up front and rear, but rejects sound from the sides.
3) The action of turning a followspot on a performer. (e.g. ‘that was a good pick-up’, ‘your next pick-up is downstage left’). A BLIND PICKUP is on a moving performer and requires good hand-eye co-ordination. A SET PICKUP is on a specific area, is preset, and is made on a cue from the stage manager. A SIGHT PICKUP is made visually by the operator to a preset position.

PILE-ON SUBMASTER
See SUBMASTER.

PIN PATCH
See PATCHING.

PIN PLUG
See PATCHING, PHONO PLUG.

PIN SPOT
1) A lantern focused very tightly on a small area (eg an actors head)
2) A luminaire used widely in disco installations, consisting of a low voltage (6V) Par 36 lamp (lamp code is 4515) with a very narrow beam in a metal case with built in transformer.
Pin Spots are ideal for lighting MIRRORBALLs.

PIPE ENDS
Lanterns hung at the very ends of lighting bars – used for crosslight and very common in dance or musical theatre.

PLAN
A scale drawing showing a piece of scenery, the whole set, lighting layout etc from above. Lighting plans are usually drawn onto the theatre’s groundplan. A view from the side of the set (or a piece of scenery) is known as an ELEVATION.

PLASA / P.L.A.S.A.
Professional Lighting and Sound Association (UK).
See ESTA for the American equivalent.
PLASA website

PLAYBACK
The part of a computerised lighting control desk which enables the operator to recall cues from the electronic memory.

PLOT
1) List of preparations and actions required of technical crews during the performance (eg Sound Plot = list of sound cues and levels in running order.) In the US, the term plot refers to a plan. (eg Light Plot = scale plan showing lighting instruments). See also RUNNING PLOT, STATE PLOT.
2) The basic story thread running through a performance / play which gives the reason for the character’s actions.

PLOTTING SESSION
Time during which the plot for each department is prepared (eg Lighting Plotting session)

POINT CUE
A cue inserted during / after plotting between two existing cues. (eg 8.5 is inserted between cues 8 and 9). Most computer lighting desks have the ability to either insert an additional cue in a sequence, or to link to another cue out of the sequence, and then link back again. Inserting cues into a plotted sequence on a manual lighting desk is more awkward, because it is a running plot (where only the changes between cues are noted down).
Sound cues within a sequence should have lettered cues (e.g. 8A is a fade up of Cue 8 and 8B is the fade out).

POLE OPERATION
A mechanical means whereby pan (horizontal rotation), tilt (up and down) and focus of a lantern may be adjusted by a pole from floor level. Commonly used in TV & Film studios where fast resetting of positions is necessary.

POWERCON
Power connector with the same body design as the SPEAKON speaker connector. Manufactured by Neutrik. Used extensively on lighting patch panels (at least in the UK) due to its smaller physical size.
Neutrik Powercon page

PRACTICAL
Any object which appears to do onstage the same job it would do in life, or any working apparatus (eg light switch or tap). Light fittings which have to light up on the set are called Practicals.

PREFOCUS CAP
A type of lamp base which ensures that the filament is correctly lined up relative to the reflector and lens.

PREHEAT / PRE-HEAT
Smoother lighting builds from zero are achieved when a lamp filament has been warmed (at approx 15%) in the previous state.
Preheating lamps MAY prolong the life of the lamp by reducing the thermal ‘shock’ of going to 100% instantly. It’s good practice to preheat lamps where possible, and some computerised lighting desks provide this function at the push of a button.
See also RIG CHECK.

PRELUDE
(Trade Name) Range of 500W/650W lanterns produced by Rank Strand (now Strand Lighting) in the UK.
Strand Lighting website
Strand Archive

PRESET
1) Anything in position before the beginning of a scene or act (eg Props placed on stage before the performance, lighting state on stage as the audience are entering.)
2) An independently controllable section of a manual lighting board which allows the setting up of a lighting state before it is needed. Each preset has a master fader which selects the maximum level of dimmers controlled by that preset.

PREVIEW
1) A performance (or series of performances) before the ‘official’ opening night. Previews are used to run the show with an audience before the press are allowed in to review the show. This allows technical problems to be ironed out while ensuring the cast and creative team get audience feedback. Tickets are sold at reduced price and help to spread word of mouth interest in the show.
2) A function on some memory lighting control desks with video mimics. Preview enables the operator to see the levels of dimmers and other information in a lighting state other than that on stage.

PREVISUALISATION
Computerised tools which enable design teams to show directors and other members of the production team how lighting or scenic automation will look before the set is even built. See WYSIWYG.

PRIMARY COLOURS
The primary additive colours of light are red, green and blue, and the subtractive colours are cyan, magenta and yellow.

PRODUCTION DESK
Table in the auditorium at which director/designer etc sit during rehearsals (especially technical rehearsals). Usually has its own lighting and communications facilities.

PROFILE
1) A type of lantern with at least one plano-convex lens which projects the outline of any chosen shape placed in its gate, sometimes with a variable degree of hardness/softness. Profiles include four beam-shaping metal shutters, a gate to take an iris or gobo and an adjustment to make the beam smooth and even (‘flat’) or hot in the centre (‘peaky’). See Bifocal Spot, Zoom Profile.
2) Shaped piece of scenery added to the edge of a flat instead of a straight edge. Also known as a cutout.
Types of lantern

PROJECTION
1) Slides are used to project still archive images or textures. Libraries of slides contain images for every occasion. Kodak Carousel projectors are the industry standard, and some types can be linked to a controller to perform complex dissolves and fades from one projector to another. More powerful projectors are available using very intense discharge sources and large format glass slides to produce a massive image.
2) Lighting effects : Moving cloud / rain / fire effects can be achieved using a powerful lantern known as an effects projector with a motorised glass disc painted with the required effect. An objective lens is required in front of the disc to focus the image. See Effects.
3) Gobos : See GOBO.
4) Film : 35mm film projection is common in many theatres as a device for keeping the building open to the public when productions are in preparation. 16mm film projection is used in smaller venues. Film projection can, of course, also be integrated into a performance.
5) Video : Video projection is now being used to bring television pictures to the large screen. Cheaper than using film, but the image quality is not as good. Video projection equipment can also be more difficult to set up. Images can be front projected or back/rear projected depending on the amount of space and the effect required. For example, if actors are required to walk in front of the screen and not have the image appearing on them, back projection is the only answer.
See LCD, DLP, SCREEN.

PROTOCOL
See MULTIPLEX.

PSU
Power Supply Unit.

PULL
The amount of electrical power required by a touring show in a venue.

PVC TAPE
Plastic insulating tape used for taping cables to bars and for securing coiled cables. Neater and cheaper than Gaffa tape. Also known as LX tape.

PYRO
1) See PYROTECHNICS
2) Short for Pyrotenax, a brand name (UK) of Mineral Insulated Cable.

PYROTECHNICS
(Pyro) Chemical explosive or flammable firework effects with a manual detonation. Usually electrically fired with special designed fail-safe equipment.
There are many different variations of pyrotechnic effects available. The categories are as follows:
Theatrical Flash – a flash and a cloud of smoke
Maroon: produces a very loud bang. Must only be detonated inside a bomb tank covered with a protective mesh.
Gerb: version of the Roman Candle firework, throwing a shower of sparks into the air. Possibly named from the French ‘Gerbe’ meaning a sheaf of wheat, due to it’s shape.
All pyrotechnics should be used with close reference to local licensing laws, and the manufacturers instructions. Professional advice should be sought before the first use of effects.
Some territories only permit licenced pyrotechnicians to use these devices.

QUARTZ HALOGEN
See TUNGSTEN HALOGEN.

QUARTZCOLOR
(Manufacturer) Range of TV/Film lanterns marketed by Strand Lighting.

R & V
(Manufacturer) Reiche & Vogel. German manufacturers of low voltage beamlight. Now sometimes used to describe any beamlight.
Reiche & Vogel website

RADIO CONTROL
System whereby battery-powered practicals / props on stage can be controllable from offstage with no connecting leads.

RAT STAND
Illuminated music stand (named after manufacturer ?).
R.A.T. website

RCD
Residual Current Device. Protects the user against short circuit (earth faults) and earth leakage caused by damaged cable or faulty equipment. A RCBO is a combined MCB and RCD, protecting against earth leakage/short circuit and overload. Known as a GFI (Ground Fault Interruptor) in the USA.

RDM
Remote Device Management. New lighting control protocol (officially ANSI E1.20 standard) currently under development at ESTA, which allows two-way communication over standard DMX512 cable. See also MULTIPLEXED SIGNAL.

RE-RIG
To change the lighting rig after the last performance of one show to the positions for the next show.

REAR PROJECTION
See PROJECTION.

REDHEAD
800W open-faced adjustable flood lamp used in film / TV lighting. So-called because of it’s red paint finish. See also BLONDE.

REMAINDER DIM
A command used on Strand Lighting memory control desks which is comparable to the SOLO function on other desks. For example, entering CH 5 REM.DIM will put channel 5 at full and will put everything else at zero.

RESISTANCE DIMMER
A now obsolete method of dimming which decreases the current available to the load by introducing a variable resistance between supply and load. The excess current is converted into heat. Based around a rheostat.

RESOLUTION
1) The point during a drama when the plotline reaches a conclusion, and conflict is resolved.
2) A measure of the quality of a video display
3) The quality of a sound sample is measured by the sample rate (e.g. 44.1kHz is CD quality sample rate) and the resolution (either 8 bit or 16 bit normally).

RESTORE
A cue to resume or return to any previous state, setting or function. (e.g. ‘at the end of the dance number we restore to a warm general cover’).
Submitted by Bert Morris.

RETROFIT
A modification that can be made to an existing piece of equipment after purchase to bring it up to date.

RFU
Remote Focus Unit. Name used by ETC for a remote control for the lighting desk. Same as RIGGERS CONTROL.

RIG
1) The construction or arrangement of lighting equipment for a particular production.(noun)
2) Installing lighting, sound equipment and scenery etc for a particular show.(verb)

RIG CHECK
(also known as LAMP CHECK) The process of checking all lanterns in the rig are working correctly prior to each performance. Should be done daily in sufficient time to change a lamp if necessary.
Most venues do not have the electrical capacity to run all lanterns at full for a rig check, so a level of 25% is normally used.
N.B. this is NOT the same as preheating – a rig check happens before each performance and involves the whole rig, and preheating involves individual lanterns/dimmers and happens before a cue in which that lantern appears.

RIGGERS CONTROL
A remote control for a lighting desk which enables dimmer channels to be called up from the stage when rigging or focusing. Usually battery powered, sometimes with infra-red (cordless) control. A Designers Control allows whole memories to be called up and/or played back, as well as individual dimmers.

ROCK DESK
Lighting control desk designed for rock concerts, the main feature of which is the ability to group a set of dimmers under the control of a series of flash buttons, enabling the operator to ‘play the lights’ in time to the music. These desks usually have a very good lighting effects capability.

ROSCO LABS
(Manufacturer) USA based manufacturer of lighting gels and scenic products. See COLOUR FILTER.
Rosco Labs website

RUNNING LIGHTS
US term for the blue working lights used backstage during a performance.

RUNNING PLOT
A plot giving details of the changes between cues, as distinct from a state plot which gives the whole state of the system at any time. For example, a lighting plot on a manual board is normally a running plot. It is difficult to start a running plot half way through; often the operator has to go back to the beginning and work through until the required point is reached. However, it contains the minimum information necessary to perform the cues, and is therefore more efficient on a manual lighting desk or complex sound setup.

SAFARI
Lighting control software originally manufactured by AVAB Scandinavia. Safari software is now maintained by ETC.
AVAB website
ETC website

SAFETY CHAIN
Chain or wire fixed around lantern and lighting bar or boom to prevent danger in the event of failure of the primary support (eg Hook Clamp). A requirement of most licensing authorities. In the UK, current legislation

SAMOILOFF EFFECT*
TO BE DEFINED

SANDNET
Network operating system integrating standard communications protocols with a multitude of industry and manufacturer-specific control protocols.
Sand Network Systems website

SATURATION RIG
An arrangement of lanterns in which to maximum number of spotlights is placed in every possible position.

SAVE
(US especially) To extinguish a particular lighting instrument (e.g. ‘Save 14′). The instrument’s lamp (and its colour filter) are thus saved for another occasion. Used when setting up lighting states.
Submitted by Peter Neilson

SCANNER
General name for a moving mirror lantern, especially those used in discos, rather than the more flexible units used in theatre.

SCENE
1) A pre-programmed lighting state which can be faded in and out during a one night show when there’s no time for plotting.
2) A subdivision of a play. See also ACT.

SCOOP
A special type of floodlight consisting of a lamp mounted in a large ellipsoidal reflector. The body of the instrument is usually circular which means a soft edged circular beam is produced. A standard FLOOD has a rectangular body.

SCR
Silicon Controlled Rectifier. See THYRISTOR.

SCREEN (PROJECTION)
Many types of projection screen are available. Some are multi-purpose, some only for front projection, some only for back projection. If a screen is not self-supporting, it often has eyelets around the outside edge which are used to ‘lace’ the screen onto a larger frame.
See also PROJECTION.

SCRIM
1) A coarse gauze
2) A fine metal mesh used to reduce the intensity of light from TV lanterns without affecting colour temperature.

SCROLLER
See COLOUR CHANGER.

SECONDARY LIGHTING
Separately powered lighting system for use throughout the building in the event of failure of the primary system. Usually battery powered. Maintained lighting is on all the time, regardless of changes in the stage lighting, and is battery backed-up.
Non-maintained systems only light in the event of power failure or an alarm condition.
Secondary lighting systems should be regularly checked by an electrician to ensure they operate correctly.

SELECON
(Manufacturer) New Zealand-based manufacturer of theatre lanterns.
Selecon website

SEMAPHORE
See COLOUR CHANGER.

SEMIOTICS
The study of signs – many conventions in lighting design rely on signs (blue must be night-time, red is evil etc.)
Semiotics for Beginners

SERIES SPLITTER
An adaptor consisting of a plug and two sockets wired in series. Enables two identical 110 Volt loads to be safely run from a 240 Volt supply (UK).

SHIFTER
The common Australian term for AJ’s, c-wrenches, spanners etc.

SHINS
The lowest lantern on a lighting boom. Named because of the proximity of sharp parts of the lantern to the flesh of the lower leg. This especially applies to standard dance lighting, when the lanterns are positioned at optimum height to light dancers on the stage floor. When the boom is lighting scenic items or large groups, the lanterns may be higher up the boom and the term will no longer apply.
Also known as SHIN BUSTER. The other lanterns on the boom are known as MIDS and HEADS.

SHORT NOSE
Normally refers to a Short-Nose Parcan – a lighting instrument that uses a normal size PAR lamp, but has been shortened to either make it less obtrusive, or to get a wider beam angle.

SHUTTER
Part of a profile lantern. Metal blade which can be used to shape the edge of the beam. Shutters (normally four) are located in the gate at the centre of the lantern. Similar in effect to barndoors on a Fresnel or PC lantern, but a lot more flexible.

SIGHTS
A pair of metal rings attached to the side or top of a followspot which enables the operator to accurately line up the beam (by looking down the length of the followspot through the rings) before turning it on. See GHOSTING.

SILHOUETTE
1) To light the cyclorama or a piece of upstage set in such a way that the actors are cast into shadow. Can be a very dramatic effect.
2) (Trade Name) A range of 2000W lanterns manufactured by CCT in the UK.
CCT Lighting website

SILK
A special type of diffusion frost filter which stretches the light in one direction. Especially useful for lighting large cycloramas with a limited number of lanterns, or for lighting an elongated object (eg a staircase) with one lantern.

SIRIUS
(Trade Name) Manual/memory lighting control desk previously manufactured by Zero 88 in the UK. Available as Sirius 24 (24 channels) or Sirius 48. Desks can be linked together.
Zero 88 website

SIX LAMP BAR
An internally-wired lighting bar, designed for touring, with six socket outlets terminated in a multi-way connector (e.g. SOCAPEX or LECTRIFLEX). Often pre-rigged with lanterns (eg Parcans). Stored in Meatracks. A bar pre-rigged with Parcans is sometimes known as a PAR BAR.

SLIDE
See PROJECTION.

SMOKE
See SMOKE MACHINE

SMOKE DETECTORS
Many theatre buildings have complex fire alarm systems installed. Some theatre spaces have smoke detectors in them, which trigger a fire alarm when the space fills with smoke. The use of SMOKE MACHINES in these spaces can (and does) result in expensive call-outs of the fire department and evacuated auditoria.
There are special heat-sensitive detectors called RATE OF RISE detectors which trigger a fire alarm when the temperature rises faster than it should normally. Properly calibrated (and regularly tested) these can be as effective than the smoke detectors (which work by ‘seeing’ smoke particles in the air). If it’s not possible to get Rate of Rise detectors installed in your theatre space instead of smoke detectors, you may be able (subject to local building regulations and local fire department advice) to isolate the smoke detectors for the duration of the performance when you use smoke effects. Properly designed alarm systems incorporate timed isolation, so that smoke detectors are only off for a specific period, and automatically come on after that period.

SMOKE MACHINE
A Smoke Machine or Fogger is an electrically powered unit which produces clouds of white non-toxic fog (available in different flavours/smells) by the vaporisation of mineral oil. It is specially designed for theatre & film use.
A Haze machine, Hazer or Diffusion Fogger is used to produce an atmospheric haze, rather than clouds of smoke, and is used by many lighting designers to reveal airborne light beams.
The first smoke machines came onto the market in the late 1970′s.
See also CRACKED OIL, DRY ICE.
It’s essential to know whether your venue uses SMOKE DETECTORS on the fire alarm system. See that entry for more information.

SNAP
A lighting or sound cue with no fade time – the cue happens instantly.

SNAPPER
See GRELCO.

SNOOT
See TOP HAT.

SOCA
See SOCAPEX.

SOCAPEX
A multipin connector which can carry a series of lighting or sound circuits. Very robust and designed for touring. Available in 19 pin (6 circuits) and 37 pin (12 circuits) configurations. Sometimes shortened to SOCA. See also LECTRIFLEX.

SOFT LIGHT
Asymmetric flood light used as a fill light in TV studios to eliminate shadows and balance the key light.

SOFT PATCH
See PATCHING.

SOLO
1) On a sound desk, the solo button on each input channel silences all other inputs so that channel alone can be heard. Dangerous to use during a show, but can be useful for fault-finding or testing equipment.
2) On a lighting desk, SOLO mode kills all other channels except the single dimmer you’re working with. Again, can be useful for identifying a channel in a large rig, but can be dangerous during a show. Some desks allow you to assign flash buttons to SOLO mode which will turn off all channels except those loaded into that flash button or submaster. This can be used for a quick lightning effect (but it’s a bit tacky). On Strand Lighting memory desks, the solo function is called REMAINDER DIM (or REM DIM).

SON ET LUMIERE
An audiovisual entertainment often based on an historical theme (and often produced in a historically relevant location). A voice narration is often used and lighting / special effects set the mood and portray certain events in time with the narration. Often used to refer to a performance with no performer where the meaning is communicated solely with technical effects.

SOUND TO LIGHT
A facility which can link the effects panel on a lighting board to an audio input which detects treble, mid and bass beats, and can flash lights or trigger effects in time to those beats. First used when electronics allowed it cheaply in the late 1960′s/

SOURCE FOUR
(Trade Name) (Also known as S4) Range of lanterns manufacturer by ETC.
ETC website

SPARKY
See LAMPIE.

SPECIAL
A lantern within the lighting rig which is required for a specific moment or effect within the performance, and is not part of the general cover lighting. See GENERAL COVER.

SPIDER
Adaptor to connect many lanterns to one multicore cable. Consists of multipin connector (typically Socapex or Lectriflex), short length of cable, then a number of sockets related to the number of circuits in the cable.

SPIGOT
An adaptor screwed onto the hanging bolt of an instrument to enable it to be used on an upright stand.

SPILL
Unwanted light onstage.

SPILL RINGS
Concentric rings attached to the front of a beamlight (eg Strand Pageant) to contain spill.

SPLITTER
See ADAPTOR.

SPOT
To reduce the beam size of a fresnel or pc lantern by moving the lamp further from the lens. (e.g. ‘Could you spot that down a touch, please?’). See also FLOOD.

SPOT SEAT
Chair for suspending followspot operator above a stage / auditorium. Normally rigged on a truss system. The operator gets to the seat up a wire rope ladder, and is strapped into the seat. He or she will normally wear a harness when getting to the chair for extra safety. The seat itself is an adapted car ‘bucket’ seat.

SPOTLIGHT
General term for any lantern with a lens system. See Fresnel, PC, Profile.

STAGE BOX
A connection box at the end of a lighting or sound multicore cable.

STAGE ELECTRICIAN
Member of the electrics staff whose responsibility it is to set or clear electrics equipment during scene changes. May also carry out colour changes on booms etc.

STAGE LEFT / RIGHT
Left/ Right as seen from the Actor’s point of view on stage. (ie Stage Left is the right side of the stage when looking from the auditorium.)
Stage Right = OP (Opposite Prompt) French: Cot‚ Jardin, Netherlands: Toneel Links (translates to Stage Left!)
Stage Left = PS (Prompt Side) French: Cot‚ Cour, Netherlands: Toneel Rechts (translates to Stage Right!).
NB: The Netherlands, Portugal and Germany use the opposite to the rest of Europe; i.e. Stage Left UK = Stage Right. The directions are seen from the director’s and audience’s perspective, NOT the actors. In Portugal Isquerda (left) is the equivalent of UK Stage Right and Direita (right) is the equivalent of UK Stage Left.
Stage layout diagram
Derivation of Court & Garden

STAND-BY / STANDBY
1) A warning given to technical staff by stage management that a cue is imminent. The member of the stage management team calling the cues will say ‘Standby Sound Cue 12′. Technicians acknowledge by saying ‘Sound Standing By’.
In the US, the word ‘Warning’ replaces ‘Stand-by’.
2) A member of the cast of a musical or play who understudies one (sometimes more) of the principal roles but is NOT also in the chorus. A standby often won’t even be required to be at the venue at each performance unless he/she is called in to perform in the role for which he/she is an understudy.
See also ALTERNATE, SWING, UNDERSTUDY.
Additional information submitted by Pierce Peter Brandt

STARCLOTH
See CLOTH.

STARLETTE
(Trade Name) Range of 1000W lanterns produced by CCT in the UK.
CCT Lighting website

STATE
In lighting terms, a lighting ‘picture’ ; each lighting cue results in a different state (or a modified state).

STATE PLOT
See RUNNING PLOT.

STEEL
1) Refers to a steel blue / pale blue lighting gel. (Lee 117) (e.g. ‘Use the Steel General Cover for the scene in the castle’). See also STRAW.
2) Many set construction now uses steel frames with timber cladding. Steel is stronger and lighter weight compared to timber of the same size.
3) Generic term used for a plain wire rope sling. Also used when referring to roof structural steel and individual steel beams or scaffold materials and so on.
Additional information submitted by Chris Higgs.

STEP
1) A control on some lighting effects boards which enables the operator to ‘step’ through a chase effect in time to music etc.
2) Each separate component of a lighting effect is called a step. A chase effect with four channels flashing on will have four steps.

STRAND
1) (Manufacturer) Maker of lanterns, lighting desks and dimmers in the UK and Worldwide.
2) The bundle of individual fibres or wires that make up one of the helical elements in a rope.
Strand Lighting website
Strand Archive

STRAW
Refers to a pale yellow lighting gel. (e.g. Use the Straw General Cover for the garden scene). See also STEEL.

STRIPLIGHT
1) A thin linear filament lamp similar to an Architectural, but having contacts at the ends of the lamp. Available clear or opaque.
2) (US) See BATTEN.

STROBE
Device giving a fast series of very short intense light flashes which can have the effect of making action appear intermittent. Because strobe lighting can trigger an epileptic attack in sufferers, the use of a strobe must be communicated to the audience before the performance begins. Strobes should be synchronised so that they operate outside the dangerous frequency band 4 to 50 flashes per second. (i.e. a strobe should operate at less than 4 flashes per second, or more than 50 flashes per second). If the effect is momentary, this rule may be relaxed. Strobes must never be used in public areas where there are changes of level or steps.
Always seek the advice of the licensing authority if you are in any doubt about the safety of strobe effects.

SUBMASTER
Fader on a lighting desk which can have a lighting state recorded onto it for additional control, or to use when manually mixing lighting states for music concerts or one-off events.Lighting desks normally have a series of submasters (12 or 24 are common) which can have states, cues or effects loaded onto them. Some desks can have submasters set to inhibit the main output (known as INHIBITIVE SUBMASTER. For example, the FOH lighting can be loaded onto a submaster which is then brought down as the house tabs are flown in between curtain calls to block light spill onto the tabs).
Multiple cues can be recorded onto some submasters through the use of pages.
A PILE-ON submaster can be used to add it’s contents to the existing lighting state. Any number of pile-on submasters can be used in combination to modify a state.

SUBTRACTIVE COLOUR MIXING
See COLOUR MIXING.

SUPER TROUPER
(Trade name) Manufactured by Strong International – a range of high intensity followspots designed for large scale permanent installations or large touring shows. The Super Troupers use Xenon lamps and vary from 1600 – 2000W.
The Super Trouper is the best known of all stage lighting instruments outside of the industry due to Abba’s song ‘Super Trouper’.
Abba’s Super Trouper lyrics
Strong International Entertainment Lighting website

SVOBODA
Low voltage lighting batten used to create a light curtain. Named after Josef Svoboda, the Czech scenographer (1920 – 2002). The original Svoboda light batten is still manufactured by ADB. Josef Svoboda contacted ADB when he was looking for a manufacturer for his idea.
ADB website
Submitted by Andre Broucke

SWARBIES
3 or 4 , 500 or 1000 watt flood lamps mounted on a wooden skid,used as cyclorama bottom lighting or in between scenery groundrows. Probably derived from German theatre lighting company, Schwabe.

SWATCH
A sample of fabric to demonstrate the material to use on a costume or set design, or a sample of lighting gel. A catalogue of all the gel colours made be a particular manufacturer is called a SWATCH BOOOK.

SWL
Safe Working Load.

T
Lighting Industry Forum code which identifies the (original) recommended usage of different lamp types. T coded lamps are for theatrical use, and have a colour temperature of 3000°K. See also CP, A1, P2, K.

TAB DRESSING
Lighting focused onto the front tabs to before the show starts.

TAILS
Also known as BARE ENDS, TAILS refers to a cable or set of cables with a connector at only one end which is used for connecting a company’s equipment directly to the mains supply in a venue. The connection should only be made by a qualified electrician with the power off!

TALLESCOPE
(Trade Name) A retractable alloy vertical ladder on an adjustable wheeled base. The platform at the top is just large enough to hold one person. Used for rigging lanterns, focusing etc. Collapsible enough to fit through a standard doorway. Outriggers are used to stabilise the tower from falling sideways. Two people are used to move and steady the tallescope. Sometimes known as a ‘TALLEY’.
Photo of Tallescope

TANK TRAP
See BOOM BASE.

TECHNICAL REHEARSAL
Usually the first time the show is rehearsed in the venue, with lighting, scenery and sound. Costumes are sometimes used where they may cause technical problems (eg Quick changes). Often a very lengthy process. Often abbreviated to the Tech.
A DRY TECH is without actors to rehearse the integration of lighting, scenic changes etc. It follows that a WET TECH is a full technical rehearsal with actors and all technical elements, although this term isn’t used as often as DRY TECH.
A PAPER TECH is a session without the set or actors when the technical and design team talk through the show ensuring everything’s going to work as planned. Stage Managers can use this session to ensure all is written correctly in the Prompt Book.

TEMPLATE
See GOBO.

TESTING AND TAGGING
Australian equivalent of the UK ‘PAT’ Test – a regime for testing electrical equipment for safe operation and then logging the results.

THREEFER
An adaptor which enables three pieces of equipment to be connected to a single outlet or cable. Great care should be taken not to overload the circuit. See also TWOFER and GRELCO.

THROW
Distance between a light source (e.g. lantern or projector) and the actor or object being lit.

THYRISTOR
Also known as an SCR (Silicon Controlled Rectifier). An electronic switch which will pass current when triggered until the current passing through it falls to zero. Essential component of stage lighting dimmers. See also TRIAC.

TILT
1) Up and down (vertical) movement of a lantern, camera or moving light. See also PAN.
2) Feature on pinball machines which detects excessive movement of the case. Only related to theatre in connection with the musical ‘Tommy’.

TIME
The facility on memory lighting boards for playing back timed fades at the touch of a button.

TOP HAT
Also known as HIGH HAT or SNOOT. Cylinder of metal inserted into colour runners on the front of a parcan or other lantern to limit spill light.

TRANSFORMATION
An instant scene change, often effected by exploiting the varying transparency of gauze under different lighting conditions.

TRAVERSE
Form of staging where the audience is on either side of the acting area.
See also IN THE ROUND, END ON, THRUST.

TRIAC
(Triode Alternating Current switch) Electronic Semiconductor device which is an integral part of modern dimmers. When a current is applied to a triac, it starts conducting, and continues until the current passing through it falls to zero. Whereas a thyristor can only conduct half of the AC wave, a triac (as long as it’s triggered at the appropriate point) will conduct both halves of the wave. See further explanation below.
Further explanation

TRIPE (bundle)
Bunch of cables tied or taped together into a single unit.

TRS
1) Tough Rubber Sheath. Jargon for any Rubber-sheathed mains cable.
2) Tip Ring Sleeve. The three contacts on a stereo jack audio connector.

TRUNKING
Metal or plastic wall-mounted enclosure for cables. Box shaped in cross-section.

TRUNNION ARM
U-shaped bracket between the hook clamp and the main body of a lighting instrument, enabling it to be tilted to any angle.

TRUSS
A framework of alloy bars and triangular cross-bracing (usually of scaffolding diameter) providing a rigid structure, particularly useful for hanging lights where no permanent facility is available. Very often box-shaped in cross section, so known as BOX TRUSS. This type of truss is useful for touring as lanterns / speakers etc can be hung inside the truss which protects them when loading and takes up less space in the truck.

TUBULAR WAVE RIPPLE
See EFFECTS.

TUNGSTEN HALOGEN
A standard tungsten filament lamp loses its brightness in its’ lifetime. Tungsten Halogen lamps use a Quartz envelope (‘bulb’) filled with halogen gas to give an almost constant colour temperature. See Halogen Cycle.

TWOFER
A two-way adaptor. See GRELCO.

ULTRA-VIOLET (UV)
Short wavelength source of light at the end of the visible light electromagnetic spectrum which causes specially treated materials to fluoresce on an otherwise blackened stage. Used for special effect and for lighting onstage technical areas (eg Fly Floors). Ultraviolet sources designed for stage use are known as Black Light sources (also known as UV-B) and have all harmful radiations filtered out.
Black Light is used extensively in the Czech Republic where stunning effects are achieved on stages lined with black velvet. See the Image Theatre website for more.
Image Theatre, Prague

UNIVERSE
TO BE DEFINED.

UPLIGHT
Light from below the actors – from a light source on the stage floor.
contre-plongée

UPSTAGE
1) The part of the stage furthest from the audience.
2) When an actor moves upstage of another and causes the victim to turn away from the audience he is ‘upstaging’. Also, an actor drawing attention to himself away from the main action (by moving around, or over-reacting to onstage events) is upstaging.
Stage layout diagram

USITT
United States Institute of Theatre Technology.
USITT Website

VARI*LITE
Trade name for a range of ‘intelligent’ moving lights and control equipment. Identified by VL numbers. The VL1 model was introduced in 1980 for a Genesis tour by Showco, USA.
Vari*Lite Website

VARIAC
A trade name for an autotransformer (formerly) used to dim lighting by tapping a selected reduced voltage off the transformer’s winding. Not to be confused with resistance dimming.
Submitted by Peter Neilson

VIDEO
See CCTV.

VIRTUOSO
(Trade Name) Moving light control console made by Vari*Lite.
Vari*Lite Website

VISUAL CUE
A cue taken by a technician from the action on stage rather than being cued by the stage manager. Often abbreviated to ‘Vis’.

VL
See VARI*LITE.

VOLTAGE
The pressure at which electric current is available. The UK standard voltage is 230 Volts. The American standard is 110 Volts.
The scientific name for Voltage is Electromotive Force.

VPLT
German Professional Lighting and Sound Association.
VPLT Website

WARP
The first zoom profile spotlight with ring control and 4 framing shutters which are fully rotatable.
ADB website

WASH
1) A lighting cover over the whole stage (e.g. ‘We’ll use the red wash for the hell scene’)
2) A lantern which produces a large spread of softly focussed light (e.g. the VL4 and Mac 600 are wash luminaire).

WATER CRACKER*
Device which produces a thin haze in the air by ‘cracking’ water droplets.

WATTAGE
See WATTS.

WATTS
Unit of electrical power derived from the current (or ‘quantity’ of electricity) multipled by the voltage (or ‘pressure’ at which the current is delivered). Stage lighting equipment is rated in Watts (or Kilowatts – 1kW being equal to 1000W). This refers to the amount of power required to light the lamp. A higher wattage lamp requires more power and gives a brighter light output.

WAVELENGTH
The distance from one point on a vibrating wave to the same point on the next wave. The lengths of the sound waves (wavelengths) we can hear range from one inch to 40 feet. High frequency sounds have short wavelengths (and are more directional), low frequency sounds have long wavelengths (and are less directional). In lighting terms, blue light is short wavelength, green is medium and red is long wavelength. Beyond visible light are the short wavelength Ultra Violet light and the long wavelength Infra Red light. Wavelengths of light are measured in Angstroms.
See also FREQUENCY.

WHITWORTH
Pre-metric standard thread for bolts and associated fittings in the UK. (Pre 1972)

WIGGLY MIRRORS
Slang for so-called ‘Intelligent’ lights with moving mirrors.

WINGS
1) The out of view areas to the sides of the acting area.
2) Scenery standing where the acting area joins these technical areas.

WORKING LIGHTS
1) High wattage lights used in a venue when the stage / auditorium lighting is not on. Used for rehearsals, fit-up, strike and resetting.
2) Low wattage blue lights used to illuminate offstage obstacles and props tables etc. Known as Wing Workers.

WRENCH
American for SPANNER.

WYSIWYG
Acronym of ‘What You See Is What You Get’. Mainly used in the context of a software tool for lighting design and production administration. Capable of stunning 3D rendering of lighting states, and direct connection to a lighting control desk. Enables accurate pre-visualisation of lighting designs and greatly increases the understanding between director / producer and lighting / scenic designer in the early stages of a production.
WYSIWYG product details

XENON
High output discharge lamp commonly used in Strobe lighting. Some followspots also use Xenon lamps. Xenon lamps have colour temperature of between 5600 – 6500°K.
See also DISCHARGE LAMP.

XFADE
See CROSS FADE.

XLR
Multipin metallic connector. (3 pin for normal sound use, 5 pin for DMX, Colour Scrollers etc). Sometimes called Cannons after the original manufacturer.
The UK standard for wiring the 3 pin connector is as follows : Pin 1 (Screen), Pin 2 (+ve / ‘hot’), Pin 3 (-ve, ‘cold’). (Xternal, Live, Return).
A 5 pin connector for DMX512 use has the following connections: pin 1 = screen, pin 2 = data -ve (‘cold’), pin 3 = data +ve (‘hot’), pin 4 and 5 are not used by many manufacturers. A comparison is made between the signals carried by the two data cables, and any differences are cancelled out, meaning that noise/data error reduction is very effective.

YO-YO
A device used for remotely moving a gobo in one plane whilst it is in the lantern. Gives the effect of a lateral movement (door opens, train passes etc.)

YOKE
The TRUNNION ARM of a lantern.

ZARGES
(Manufacturer) German manufacturer of a range of ladders. Commonly refers to the 3-part ladder used on many stages around Europe.
http://www.zarges.de/

ZERO 88
(Manufacturer) UK-based manufacturer of control and dimming equipment.
Zero 88 website

ZOOM ELLIPSOIDAL
See ZOOM PROFILE.

ZOOM PROFILE
A type of profile lantern with two lenses enabling the adjustment of both size of the beam and whether it’s hard or soft focus. This adjustment of focal length allows a single instrument to find many uses in various locations around the stage. The flexibility is also essential when working with gobos. Also known (in the US) as a Zoom Ellipsoidal.

Sumber: http://www.theatrecrafts.com

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13 07 2009
Glossary / kata-kata sukar dalam dunia lighting « Blognya Kulilampu | ProjectorsArea.Com

[...] See original here: Glossary / kata-kata sukar dalam dunia lighting « Blognya Kulilampu [...]

2 11 2012
Immigration Adviser in Chelmsford

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7 11 2012
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