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

CURTAIN CALL
At the end of a performance, the acknowledgement of applause by actors - the bows.

CURTAIN LINE
1) Imaginary line across the performance space marking the point where the front tabs / curtain is flown. See also SETTING LINE, CENTRE LINE.
2) The final spoken line of the play.

CURTAIN SPEECH
Introduction given by director or theatre owner (etc.) from the stage just before the performance starts. Often replaced with a recorded announcement 'Good Evening Ladies and Gentlemen and welcome to the (insert name) Theatre. May I remind you to please switch off mobile phones and pagers as they can prove distracting to other members of the audience and the performers. Flash photography is also not permitted. We hope you enjoy the show!'.

CURTAIN TIME
The advertised start time of the performance. This may be delayed by the late arrival of a large party, but regularly starting late because of box office queues should be avoided.

CUT CLOTH
See CLOTH.

CUT-OUT
See PROFILE.

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

CYCLORAMA
Usually shortened to just 'cyc' (pronounced sike). The Cyclorama is a curved plain cloth or plastered wall filling the rear of the stage or TV studio. Often used as a 'sky' backing to a traditional set, or as the main backing for a dance piece etc. The term is often loosely applied to a blue skycloth, or any flattage at the rear of the stage. Although strictly a cyc should be curved, most cycs are flat with curved wraparound ends. A more effective backing can be obtained by hanging a sharkstooth gauze just in front of the plain white cyc which gives a hazy effect of distance.
From Greek Cyclos (circle) and Horama (view or vision).
See also BOUNCE, ISORA.

DÉNOUEMENT
The moment in a drama when the essential plot point is unravelled or explained. (e.g. 'So you see I couldn't have killed the gardener. Because I AM the gardener' (Loud organ music etc.)).

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 CAPTAIN
Member of a group of dancers in a show who is responsible for leading rehearsals and warm-ups prior to the performance.

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.

DANCER
Member of the company whose role is choreographed, and who has no spoken words.

DARK
A venue that has been closed to the public. Some theatres go dark temporarily during production periods, when the next show is in preparation on stage.

DAT (Digital Audio Tape)
See DIGITAL RECORDING.

DAYMAN
A member of the backstage staff whose employment includes work done in day-time.

DBO (Dead Blackout)
See BLACKOUT.

DBX
A tape-recording noise reduction process.

DC
Short for DIRECT CURRENT.

DCC
(Digital Compact Cassette) Manufactured by Philips in the Netherlands, this format was supposed to be the successor to the compact cassette, but Mini Disk won the marketing war. DCC was discontinued for mass market use in 1996. See DIGITAL RECORDING.

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

DEAD HANG
A rigging point direct to the grid / beams above the stage, not to a flying bar.

DEAD HINGE
A hinge used as a right-angle bracket.

DEAD LINE
A static suspension, 'drop wire' or bracing line. A suspension without any lifting power.
Submitted by Chris Higgs

DEAD OUT
To replace a hoist or winch suspension with a dead line. Once the truss or piece is at trim, to tranfer the load onto 'dead lines' and remove the hoists or lifting devices.
Submitted by Chris Higgs

DEAD ROOM
A room with very thick sound absorbers, causing a very dull sound with no reverberation.

DECIBEL (dB)
Relative measurement for the volume (loudness) of sound. One dB is the smallest variation in loudness that the human ear can detect. Also used to measure the difference between two voltages, or two currents. See ZERO DB.

DECK
1) Stage/Rostrum Floor (e.g. 'Fly that flat in to the deck')
2) Tape deck/Record deck.

DELAY
Outboard sound equipment that can momentarily stores a signal being sent to part of a P.A. system so that delayed reinforced sound reaches the audience at the same time (or just after) the live sound from the stage. Using the 'Haas Effect' the audience cannot detect the sound as amplified.

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.

DEPUTY STAGE MANAGER
Usually shortened to DSM, in the UK, this is the member of the Stage Management team who attends all rehearsals and then calls the cues / runs the book for the show. Known in some places as a Stage Director.

DESIGNER
See SET DESIGNER, COSTUME DESIGNER, LIGHTING DESIGNER, SCENOGRAPHER.

DESIGNERS CONTROL
See RIGGERS CONTROL.

DEUS EX MACHINA
Latin for God in the Machine. A mechanical device used in Greek classical and medieval drama to lower an actor playing God from the flies above the stage to resolve the conflict in a play.
The mechanical crane that carried the DEUS EX MACHINA was known as MECHANE.
The term sometimes refers to a character which has a similar function in a more modern drama.

DI BOX / D.I.BOX
Interface unit to convert the high impedance unbalanced output of an instrument (e.g. Electric guitar) into a low impedance balanced signal of low level suitable for connection to the microphone input of a mixing desk. Usually has an output jack socket so that the instruments unprocessed signal can be passed direct to the musicians amplifier. DI = Direct Injection.

DIALECT COACH
Specialist who's bought into a production to train actors in a specific dialect / accent.

DIALOGUE
The spoken text of a play - conversations between characters is dialogue. See MONOLOGUE and DUOLOGUE.

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 EFFECTS
Reverb, Delay, Phasing, Flanging, Harmonising, Chorusing. More information coming soon !

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

DIGITAL RECORDING
1) ADAM : (Akai Digital Audio Multitrack). 12 track recording onto Video 8 tape. 16 bit, 44.1 or 48kHz sampling rate.
2) ADAT (Alesis Digital Audio Tape) Digital 8 track multitrack recording format introduced in 1991. There are two formats of recording: Type 1 (16 bit) Type 2 (20 bit) at two sample rates (44.1kHz and 48 kHz) onto standard SVHS video tapes.
3) DAT (Digital Audio Tape) Cassette-like system which has much higher quality than standard audio cassettes. Introduced in 1987, and widely used in gathering sound effects, for news gathering, and for playback of music.
4) DCC (Digital Compact Cassette) Rival to DAT which also plays standard audio cassettes. DCC was discontinued in 1996.
5) Mini Disk (MD) : Uses magnetic disk technology, rather than tape. A laser heats an area of magnetic disk which is then written to by a magnetic head. When cooled, the magnetic information is read from the disk by laser. Tracks can be named, and are instant start. Very theatre-friendly system.
6) Direct to Disk : Uses the hard disk present in most PCs as the recording medium.
Alesis Website

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'.

DIPOLE
Aerial used with radio microphone systems. A relatively long aerial in two parts, with an insulator at each end, connected in the middle to a coaxial cable which then connects to the receiver.

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

DIRECT INJECTION BOX
See DI BOX.

DIRECTOR
There are many types of director.
Broadly, the role involves being responsible for the overall artistic vision of a production.
ARTISTIC DIRECTOR - Normally in charge of the programming of a venue. May also direct shows.
EXECUTIVE DIRECTOR - Manager in charge of the administration of a venue.
TECHNICAL DIRECTOR - In charge of the technical requirements of a production.
(The term LIGHTING DIRECTOR is used in the UK for a TV Lighting Designer).

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.

DISTORTION
Usually undesirable result of overloading sound equipment. Reducing the levels can remedy the situation.

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.

DITHYRAMB
(Greek)

DIVERSITY
A way of maximising the quality of received radio signal by using two receivers and aerials tuned to the same frequency - the circuitry automatically silently switches to the strongest signal.

DLP / D.L.P.
Digital Light Processing. Digital technology licenced from Texas Instruments which enables video projectors to deliver a brighter, sharper, more detailed digital image. The first DLP projectors arrived in 1996.
DLP technology

DMX512
See MULTIPLEXED (MUX) SIGNAL.

DMX512-A
See MULTIPLEXED SIGNAL.

DOCK
See SCENE DOCK.

DOG
Colloquial term for a wire rope grip. Occasional a rope 'dog' or a girder 'dog' - a device that clamps.
Submitted by Chris Higgs

DOLBY
Trade name for a series of noise reduction systems that have become standard on many tape playback machines. Most film soundtracks are produced using this process. Different varieties are found from Dolby B on most personal cassette players, to Dolby SR and Digital, the current state of the art for cinema.
Dolby Labs Website

DOLLY
A small wheeled platform used to move heavy items. (E.g. a piano dolly).
Also refers to a wheeled camera trolley running on tracks used in the film industry.

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.

DOOR FLAT
Scenery item consisting of a wall containing a working (practical) door.

DOOR SLAM
A small wooden box with a heavy door and various bolts and locks used to simulate slamming and other door sound effects offstage.

DOUBLE HANDLING
Moving scenery and other equipment more than necessary because it wasn't properly sorted or positioned in the first place.

DOUBLE PURCHASE
Counterweighted flying system where the cradle/arbor travels half the distance of the fly bar, leaving the side wall of the stage under the fly floors clear of flying equipment. The cradle of a double purchase system needs twice as many counterweights as that of a single purchase system balancing the same weight.

DOUGHNUT
See DONUT.

DOUGHNUT REVOLVE
See REVOLVE.

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.

DPI
Dots per inch. A measure of the resolution of a printed or computer image.

DRAMA
The academic subject area into which theatre falls.

DRAMA TEACHER
Teacher of Drama.

DRAMATIC IRONY
A dramatic device whereby the audience is aware of something that one or more characters are not, and action onstage reflects the effect of this lack of knowledge (frequently comic, but also tragic). Dramatic Irony is often used to underline plot points for the audience.
Submitted by Gregg Shanks

DRAMATIS PERSONAE
Latin for the persons (characters) in a play. The list on the front page of a script which lists the characters in the text, and sometimes their relationship to each other.

DRAMATIST
A playwright, composer or lyrisist who takes an existing story and transforms it into a play or musical.
Dramatists Guild of America

DRAMATURG
Works as an advisor/assistant to the director on the background and historical relevance of the play being produced. Also can act as a liaison between director and playwright, and can work on the text of the play (editing & revising scripts). Also advises the theatre management staff on the suitability of plays for the theatre's audience and artistic policy. See link below for more information.
What is a Dramaturg?

DRAPES
Stage Curtains. See also TABS.

DRENCHER
System of pipes arranged at the top of a safety curtain to drench it with water in the event of fire.

DRESS CIRCLE
See CIRCLE.

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 PARADE
Review by director/designer/wardrobe staff of all costumes worn by cast and paraded under stage lighting. Any defects, misfits etc. are noted or corrected before the first Dress Rehearsal.
Also known as a Costume Parade.

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

DRESSER
Member of the WARDROBE Department who helps actors with costume care and costume changes during the performance.

DRESSING (the set)
Decorative props (some practical) and furnishings added to a stage setting are known as Set Dressing. See also TAB DRESSING.

DRESSING ROOMS
Rooms containing clothes rails and mirrors (often surrounded with lights) in which actors change into their costumes and apply make-up. Dressing Room doors have a list of the actors contained within. See also GREEN ROOM.

DRIFT
1) The effective travelling distance of a suspension barrel between the lowest it can reach with the scenic piece attached and the underside of the grid. The drift will be variable depending on the depth of a scenic piece suspended beneath the barrel. ie the comment 'there isn't enough drift' will usually mean that a piece cannot be flown out sufficently high to mask.
2) The wire that is used to achieve the drift (e.g. 'pass me a 2 metre drift, please').

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.

DROP
1) See CLOTH.
2) A mechanism for dropping items from the fly tower onto the stage (e.g. Petal Drop, Leaf Drop etc.) Normally consists of a bag or box with a lid / section which can be released either by removing a pin via a control line (piece of string) or electrically using a solenoid (electromagnet).

DROP SHACKLE
The other bow shackle in a 'basket' assembly, the one that is actually screwed in use (unscrew it and the load drops!)
Submitted by Chris Higgs

DROP WIRE
The vertical wire rope used for rigging or suspending an object from a 'rigging point'. Often provided by a venue for their client to fix to (to maintain control over rigging practices). Also known as a DROPPER.
Submitted by Chris Higgs

DRUGGET
Canvas or cloth used to mask and/or protect a floor.

DRY
1) An actor forgetting the words of his script.
2) To record a sound without using any effect or other processing is to record it 'dry'. Recording with an effect is recording 'wet'.

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.

DRY RUN
A practice run, usually a Technical run without actors.

DRY TECH
See TECHNICAL REHEARSAL.

DSM
Deputy Stage Manager.

DUBBING
The process of copying a sound from one medium to another (eg onto videotape) or for backup purposes, or simply copying sound tapes.

DUOLOGUE
Part of a scene in a drama which is a scripted conversation between only two characters. See also MONOLOGUE and DIALOGUE.

DUTCHMAN
Tape or material used to cover the seams between flats or to cover hinges, prior to painting.

DV
Digital Video. Professional video format.

DVCAM
TO BE DEFINED.

DVD
Digital Versatile Disc.
DVD FAQ

DVI
Digital Visual Interface. New interface connection standard between computer and display device.
PDF article about DVI

DYNAMIC
1) A DYNAMIC LOAD employs powered lifting equipment that magnifies the loading on the supporting equipment and structure due to the need to overcome the force of gravity.
2) A DYNAMIC ROPE is one that will absorb energy by stretching.
3) DYNAMIC BRAKING is a technique where progressively firmer braking is applied, as opposed to a sudden braking force. See also STATIC.
Submitted by Chris Higgs.

DYNAMIC MIC
Robust type of microphone which picks up the sound on a diaphragm connected to a coil of wire which moves within a magnet. An alternating current is induced into the wire which provides the electrical output. Most dynamic mics have low output impedances of 200 Ohms. See CONDENSER MIC and ELECTRET MIC.

D�COR
See SET DESIGNER.

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

EARTH LOOP
Normally refers to audio interference resulting from a situation where two pieces of sound equipment are connected together over a long distance. The earths of the equipment are at different potential, and this results in an audible hum or buzz. Can be cured by removing the screen connection on one end of the signal cable. Electrical earth connections must never be removed.

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.

ECHO
A repeated sound received late enough to be heard as distinct from the source. See REVERB.

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

EDUCATION DIRECTOR
Member of the theatre staff who develops work for schools, or provides resources on current productions and runs workshops for students / school groups.

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.

EFFECTS, SOUND
1) Recorded : Often abbreviated to FX. There are many sources for recorded sound effects, from Compact Discs, to downloading from the internet. May form an obvious part of the action (train arriving at station) or may be in the background throughout a scene (e.g. birds chirping).
2) Live : Gunshots, door slams, and offstage voices (amongst many others) are most effective when done live.
See Door slam, Thunder Sheet, Rain box.
See also Compressor, Digital Effects, Exciter, Noise Gate, Reverb.

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

EKKYKLEMA / ECCYCLEMA
(Greek) Moveable platform used to move items on and off the Greek stage. The forerunner of the modern WAGON or TRUCK.

ELECTRET MIC
A condenser microphone where the capacitor plates are given a charge during manufacture which they retain, therefore requiring no external power supply.

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'.

ELEVATOR STAGE
A type of mechanised stage which has sections that can be raised or lowered.

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.

ENHANCER
Sound processing equipment which increases the presence of the vocal track in a mix by adding to the treble information in the signal. Also known as an Exciter.

ENSEMBLE
An acting group. Normally used to describe a group of actors who work well together, with no-one outshining the others.

ENTR'ACTE
An 'overture' to begin the second part or act of a performance. Often used now to describe any interval music.

ENTRANCE
1) A part of the set through which actors can walk onto the stage.
2) The act of an actor walking onto the stage (e.g. The ghosts entrance is from upstage left).

EPILOGUE
Scene or speech which follows the main action of the play and provides some insight or comment on the action. See also PROLOGUE.

EQUALISATION
The process of adjusting the tonal quality of a sound. A graphic equaliser provides adjustment for a wide range of frequency bands, and is normally inserted in the signal path after the mixing desk, before the amplifier. See FEEDBACK.

EQUITY
Short for British Actors' Equity (or American Actor's Equity Association, founded in 1913, is the labor union representing actors and stage managers in the legitimate theatre in the United States. ). The trade union of actors, directors, designers and stage managers.
UK Equity website
American Actors Equity

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.

ESCAPE STAIRS
American equivalent of Get-Off treads.

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
1) A part of the set through which actors can leave the stage.
2) The act of an actor walking off the stage (e.g. The fireman exits downstage right).

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'.

EXPANDER
See Noise Gate.

EXPOSITION
The section of plot at the start of a play which provides essential background information about the characters, their situation, and their relationships to each other.

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

EXTRA
A member of the cast with no speaking role who provides background interest in a crowd scene. Term originally derived from the film industry.

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.

FALSE PERSPECTIVE
A scenic design technique that makes a building or set appear larger than it actually is. The scale of objects that are supposed to be further from the observer is reduced to make them appear further away, even if they're not.

FALSE PROSCENIUM
A frame formed by scenic canvas or vertical flattage within the proscenium arch. Used to reduce the size of the opening when putting a small set onto a large stage.

FALSE STAGE
A special stage floor laid for a production. For example to allow trucks guided by tracks cut into this false floor, to be moved by steel wires running in the shallow (2 or 3 inch) void between the false floor and the original stage floor. A false stage is also required for putting a revolve onto a stage.

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

FARCE
Form of comedy play originated in France, using fast-paced physical action and visual comedy more than humour based on language.

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.)

FEEDBACK / HOWLROUND
A loud whistle or rumble heard emanating from a sound system. It is caused by a sound being amplified many times. (E.g. a sound is picked up by a microphone and amplified through the speaker. The microphone picks up this amplified sound and it is sent through the system again). Feedback can be avoided by careful microphone positioning, and can be reduced by use of Equalisation to reduce the level of the frequency band causing the feedback.

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

FERRULE
The metal sleeve used to form an eye termination in steel wire rope which is pressed onto the rope under pressure from a hydraulic tool. Usually made from aluminium alloy, copper or steel.
Submitted by Chris Higgs

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'.

FEV
Short for French Enamel Varnish, a stain which is a mixture of shellac and dye, diluted in methylated spirit.

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.

FIFTH BUSINESS
Now obsolete term for an actor who is neither the hero, heroine, villain or confidante in a traditional drama, but is nonetheless essential for revealing important plot points. She/he is known as Fifth Business.

FIGHT DIRECTOR
Choreographer of fight scenes on stage. Works intensively with actors training them how to avoid hitting (and hurting) each other, how to use weapons safely etc. Fight directors are highly skilled and trained and should not be substituted for someone 'who once saw Gladiator' and thinks they can repeat it!!
Society of American Fight Directors
Fightdirector.com

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

FILLS
Term for speakers additional to the main PA to improve the sound in particular locations (e.g. 'Front fills' add sound at the front of the auditorium which might be just out of range of the main PA stacks at the sides of the stage).

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

FINANCIAL BACKER
See ANGEL.

FIRE CURTAIN
See SAFETY CURTAIN.

FIRE EXIT
Particular exit(s) from a building designated by local authority fire officer to be the correct means of escape from a part of the building in case of fire. It is the responsibility of all staff and performers to ensure that all fire exits are kept clear, unlocked and accessible at all times.

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 !.

FIRE PROOFING
Treatment given to fabric, timber, drapes etc. to retard flammability. Many scenic materials require regular re-application of fire proofing treatment.

FIREPLACE FLAT
Scenery item consisting of a partial wall and a fireplace. Another BACKING FLAT is placed behind the fireplace to mask sightlines.

FIREWIRE
FireWire is another name for IEEE 1394, a high speed data transmission protocol developed in the mid 1990s by Apple which is used extensively on digital video and audio equipment and now on PCs.
The new FireWire 800 (IEEE 1394b) operates at 800Mb per second and can transmit data over 100m cables.
Apple's FireWire page

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

FIRST NIGHT
The opening night of a theatre performance often has a largely invited audience of people connected with the show but not directly involved in it (financial backers, contractors etc.)

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

FLASHBACK
A moment during the action of a play when the natural flow of time is interrupted so that a moment from the past can be presented. This can help to explain the situation characters find themselves in, or can give the audience additional insight into the characters' minds.

FLAT
A lightweight timber frame covered with scenic canvas. Now usually covered with plywood or hardboard and consequently not so lightweight. Most theatres have a range of stock flattage made to a standard size, and re-used many times.
A Rail is a horizontal batten within a flat.
A Stile is a side or vertical piece within a flat.
A Sill is the bottom rail of a flat.
See also BOOK FLAT, HOLLYWOOD.

FLEMISH EYE
Quick eyesplice in six strand wire ropes. Three adjacent strands are unlaid in order and laid up again in balance. The rope's core is removed. Strands 1 - 3 are then laid against strands 4 - 6 and re laid to form a six strand rope eye. The loose ends are tidied and a serving applied over the ends to prevent them unlaying. The splice is as strong as the rope.
Submitted by Chris Higgs

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

FLIPPER
Narrow flat hinged to a wider one.

FLOAT
1) The action of letting a large flat fall from vertical onto it's face so that it's cushioned by the air it displaces. Care must be taken when floating flats on dusty stages, as particles can get blown around as the flat lands.
2) See Floats.

FLOAT MIC
See FLOATS.

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.)

FLOGGER
Strips of canvas attached to a handle for dusting flats or scenic pieces prior to painting.

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

FLOOR PLAN
See Plan.

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

FLOORCLOTH
See Cloth.

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

FLUFF
To hesitate - to nearly forget or fumble one's lines.

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
Verb - the action of lifting an item up (out) or down (in) when attached to the Flying system.

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

FLY FLOOR(S)
High working platform at the side(s) of the stage from which the flying lines are handled. Often are also the site for socket panels for connecting flown lighting apparatus to dimmers, and also sometimes a lighting position. Known in the US as Fly Gallery.

FLY GALLERY
See FLY FLOOR.

FLY LINE
The cables and ropes which form part of the flying system.

FLY RAIL / FLYRAIL
Originally, this was the structure where the flying lines / ropes were tied off to hold scenery and other flown equipment in position. With the advent of counterweighted systems, this refers to the area where the flying system is operated. Also known as PIN RAIL or, in the UK, FLY FLOOR.

FLY TOWER / FLYTOWER
Extension of the stage walls up to allow scenery to be flown up until it is out of sight of the audience, and to support the GRID. Known as the 'flies'. The ideal fly tower should be more than twice the height of the pros. arch, and is said to have 'full flying height'. The load on the grid is transferred to the ground via the walls of the theatre. Known in the US as the Fly Loft.

FLYING
See FLYMAN, FLYING HARNESS, KIRBY WIRE, HEMP SET, COUNTERWEIGHT SYSTEM, SPOTTER, DOUBLE PURCHASE, SINGLE PURCHASE.

FLYING HARNESS
Worn by actors who have to 'fly' as part of the action of the play (typically Peter Pan or pantomimes). The flying harness is expertly fitted to the actor, and is fully tested and certified as safe before use. Cables attach to the harness normally at the hip, or the middle of the back, via a quick release locking snap hook mechanism. There are companies who specialise in this sort of wire work, and there's no excuse for not using the professionals at all times. See also KIRBY WIRE.
Flying by Foy website
Kirby's Flying
Aerial Effects website

FLYING IRONS*
Rigging hardware - MORE INFORMATION COMING SOON.

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

FLYMAN
Term for the operator of the theatre's flying system. Can be male or female, and now usually referred to as FLYPERSON. See also SPOTTER.

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.

FOH MANAGER
See FRONT OF HOUSE MANAGER.

FOLDBACK
Means by which musicians can part of the rest of the sound mix (including voices) and how their instruments sound after being amplified. Also enables actors on stage to hear musicians or effects when they cannot hear the output of the auditorium sound system.

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.

FORCED PERSPECTIVE
Set design technique. As identical objects are moved further from the viewer, they appear smaller. objects that are further away from the viewer appear smaller, and set designers can make use of this effect.

FORESHADOWING
TO BE DEFINED

FORESTAGE
That part of the stage which projects from the proscenium into the auditorium. See Apron.

FOUND SPACE
A performance space that wasn't designed to be one. Performances that take place outside the theatre (e.g. in historic buildings, factories, public areas) are said to be using found spaces.

FOURTH WALL
The imaginary wall of a box set through which the audience see the stage.

FOYER
Part of the front of house area of the theatre into which the audience first arrive on entering the theatre. The foyer normally contains: Box Office, Toilets, Entrance to auditorium, Bar, Concession / merchandising stand.

FPS
Frames per second. The UK standard is 24 fps for film, and 25 fps for television. In the USA, the TV standard is 30 fps.

FREEZE FRAME
TO BE DEFINED

FRENCH BRACE
See BRACE.

FRENCH DRAPE*
TO BE DEFINED

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.

FRENCH FLAT
A scenic flat which is flown into position, usually with French braces. Consists of a number of flats fixed together with battens. Also known as a Frenchman.

FRENCH SCENE
A scene division within a play marked (as in French drama) by the entrance / exit of an actor. These divisions can be useful in splitting up rehearsal schedules, and for marking lighting changes etc.

FREQUENCY
(measured in Hertz - Hz - cycles per second) The number of times a sound source vibrates each second. A high frequency (HF) sound has a higher pitch and is uni-directional. A low frequency (LF) sound has a lower pitch and is omnidirectional.

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 CLOTH
A cloth flown well downstage in front of which short scenes are played while big scene changes are 'silently' carried out upstage. (Common in musicals and pantomime).

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).

FRONT OF HOUSE CALLS
Announcements made by stage management or FOH staff calling the audience into the auditorium, or informing them when the performance begins. Calls are normally made at the Half (35 mins. before curtain up), the Quarter (20 mins before), the Five (10 mins), and calls normally accompanied by bar bells at 3, 2 and 1 minutes before the performance begins.

FRONT OF HOUSE MANAGER
Member of theatre management who is responsible for the day to day running of the front of house (FOH) area (as opposed to the backstage areas). He or she may oversee the running of the box office, any merchandising / catering stands as well as the ushers and any part of the building the public may enter during their visit to the theatre.
Often shortened to FOH Manager.

FRONT TABS
House curtains.

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.

FULLERS EARTH
Hydrous aluminium silicate, used in chemistry as a filter and as a binder when mixing powder paint for use on textiles.

FULLNESS
Draperies made up with deep 'gatherings' have fullness - usually requiring not less than 50% additional fabric, measured at head and foot.

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.

FX
Abbreviation for Effect, usually referring to Sound Effects, but can also mean special stage effects.

G-CLAMP
Ironmongery fitting for clamping two items into position together. See also Hook Clamp.

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

GAIN
1) The level of amplification given to a signal or of a system.
2) A control of the amount of pre-amplification given to a sound signal on its way into a mixer.

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

GENRE
A style of performance - a way of categorising different types of drama.

GERB
See PYROTECHNICS.

GERMAN MASKING
See MASKING.

GESTURE
Body or facial movements of a character during a play. Gesture can be described by the author, or suggested by the director or actor.

GET-IN
The process of moving set, props and other hardware into a theatre prior to the fit-up. (aka LOAD IN (US) and BUMP IN (Aus.))

GET-OFFS
A means for an actor to get off a rostrum, high level etc. out of view of the audience. Usually treads. Also known as ESCAPE STAIRS

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

GLASS FIBRE
A combination of a glass mat and a resin which can be formed into a strong shell. Used in prop-making.

GLAZE
Glossy finish applied as a final coat to a painted stage floor (also available as a Matt / Flat finish).

GLOVES
Used when lifting heavier lanterns or other equipment.

GLOW TAPE
Luminous yellow self-adhesive tape used to mark floors so that positions can be found in blackouts. A staple is often used to secure the tape to a floor where it might move.

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

GO
The action word used by stage managers to cue other technical departments. The word GO shouldn't be spoken by others on headsets (especially when the crew is on STANDBY) as they may assume it's the stage manager speaking.

GO UP
The time the show starts (e.g. 'What time does the show go up this afternoon?') This relates to the curtain going up at the start of the show (even if the theatre doesn't have a curtain). See also COME DOWN.

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.

GODS
Colloquial term for the Upper Circle of the auditorium.

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 CIRCLE
See CIRCLE.

GRAND CURTAIN
(US) The main house tabs in a venue. Normally a variation of blue or red in colour, although a more neutral grey is often better for scenes played in front of it, or for taking colours and gobos as tab warmers.

GRAND GUIGNOL
Shock theatre form originally from Le Grand Guignol theatre in Montmartre, Paris (opened in 1897). Specialised in portraying the macabre & gruesome to the delight and horror of the audience.

GRAND MASTER
See MASTER.

GRAPHIC
Short for GRAPHIC EQUALISER.

GRAPHIC EQUALISER
See EQUALISATION.

GREASEPAINT
Name refers to make up supplied in stick form, for application to the face or body. Needs special removing cream.

GREEN
(obsolete term) The part of the stage visible to the audience.

GREEN BAIZE
Prior to 17th century actors dying on stage, a green baize cloth was laid down on the stage to save their costumes from needing cleaning. This was also a useful anticipation builder for the audience, especially if the cloth was laid during the interval halfway into the performance.
See also GREEN ROOM.

GREEN ROOM
Room close to the stage (i.e. the green) for the actors to meet and relax. See the link below for some possible derivations of the term.
More information about Green Room

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.

GRID
1) The support structure close to the top of the fly tower on which the pulleys of the flying system are supported. Constructed from metal or wooden beams.
2) Arrangement of scaffolding from which lanterns are hung in a performance space with no flying facilities. Grid is short for GRIDIRON.

GRIDDED
Any flying piece raised as high as possible into the flys, i.e.to the limit of travel of the flying lines, is said to have been gridded.

GRIDIRON
See GRID.

GRIP
(US) Member of stage crew responsible for moving items of scenery during the show. Usually wears black. A group of grips is a GRIP CREW. This term is borrowed from the film/tv industry, where a grip handles and sets up camera equipment and lighting.

GRIPPLE
Proprietary device designed originally for agricultural use that can be used to form eye terminations in wire rope for non lifting applications.
Submitted by Chris Higgs

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.

GROUNDLING
Poorer members of the audience in an Elizabethan theatre who occupied the open-air sections of the theatre at ground level, just in front of the performance space.

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.

GUN MIC
A highly directional condenser microphone.

HAAS EFFECT
A psychoacoustic phenomenon whereby an audience will focus on an actual sound source if the reinforced sound from speakers arrives 10 - 15 milliseconds later. The setting up of delays can be time-consuming but the Haas Effect can make a vast difference to the perceived quality of the sound in a show. The delays are set up by experimentation rather than by using distance/speed/time formulae.

HALF
Call given to the actors half an hour before they will be called to the stage for the beginning of a performance. Given 35 minutes before the advertised time of commencement. Subsequent calls given are the 'quarter' at 20 minutes, 'the five' at 10 minutes and 'beginners to the stage' at 5 minutes before curtain up. See also FRONT OF HOUSE CALLS, QUARTER.

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.

HAM
Exaggerated over-acting.

HAND
(US) Short for Stage Hand (member of Stage Crew).

HANG
The 'hang' is the American equivalent of the lighting rigging session in the UK - the time when the lighting equipment is rigged.

HANGING IRON
Ironmongery fitting fixed at the bottom of the back of a flown flat to which the suspension wire is secured.

HARDBOARD*
TO BE DEFINED

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.

HD-TV
Widescreen (16:9) high-resolution digital TV format.
HD-TV basics website

HEAD
See RADIO MIC.

HEAD CARPENTER
The head of the carpentry team that builds the wooden portions of the set.

HEAD ELECTRICAN
US equivalent of the UK CHIEF ELECTRICIAN

HEAD FLY
The head of the fly crew who are responsibly for lifting scenery or other objects above the stage.

HEAD SOUND
The head of the sound department, which deals with any recorded music, sound effects, vocal reinforcement and music amplification required in the production.
See also NO.1 SOUND.

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

HEMP
A type of rope used for flying, made from fibres found within the bark of the cannabis plant.

HEMP SET
The simplest flying system consisting of a series of hemp ropes threaded through pulleys on the grid, and tied off on the fly floor on a cleat. The usual arrangement is for three ropes to be attached to a flying piece, named by their position relative to the fly floor (short, centre and long). These names are used when levelling the flying piece, and giving it a dead. The three ropes are pulled or let in together, sometimes requiring more than one person to operate. A theatre using a hemp flying system is known as a Hemp House.

HESSIAN
Coarse loose-weave cloth used to cover flats, as a scenic element, and to strengthen and give form to moulded objects (e.g masks) as they cure and harden.

HI-8
Camcorder video format designed by Sony as a follow on to its lower-quality Video 8. Uses 8mm-wide tape.

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.

HINGE
See PIN HINGE, BACKFLAP HINGE, MARIE TEMPEST HINGE.

HIT YOUR MARK
When an actor stands in the correct position (usually with regard to lighting) she/he is said to have Hit the Mark.

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

HOIST
Generic term for a lifting machine.
Submitted by Chris Higgs

HOLLYWOOD
A Hollywood is a double-sided timber flat with a much wider edge than normal. Hollywood flats are mainly used in the film/tv business. The thicker edge gives the flat extra stability, and looks more like a real wall on camera.

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
1) The audience (eg 'How big is the house tonight ?')
2) The auditorium (eg 'The house is now open, please do not cross the stage')

HOUSE CURTAIN*
TO BE DEFINED

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

HOUSE MANAGER
Duty member of theatre staff who is responsible for the Front of House staff and organisation for a particular performance. She/he is also responsible for the health and safety of the audience while they are in the theatre. See FRONT OF HOUSE MANAGER.

HOUSE TABS*
TO BE DEFINED

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

HOWLROUND
See FEEDBACK.

HTI
See DISCHARGE LAMP.

HTP
See HIGHEST TAKES PRECEDENCE.

HUM HEAD
See NOISE BOY. Term popular around the Edinburgh Festival.

HUNDRED (100) VOLT LINE
Way of sending speaker signals over long distances without losing signal strength. Transformers are used in each speaker cabinet to convert the signal from 100 Volts to a more usable level. (100V is used in the UK, 70.7V in the USA)

HYDRAULIC
A system of controlling machinery or moving scenery using oil or water under pressure to move a piston or 'ram'. Used in many large-scale shows to automate scene changes.

HYPERCARDOID
See PICK-UP

IATSE / I.A.T.S.E.
International Alliance of Theatrical Stage Employees (USA) Stage employees union.
IATSE website

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

IEM / I.E.M.
See IN EAR MONITORS

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 EAR MONITORS
Small headphones worn inside the ear by members of a pop band so they can hear the monitor mix (or the backing track they're miming to) without having lots of monitor speakers onstage. The advent of in-ear monitoring has improved the sound quality of the monitoring for these band members as they no longer have to try to hear the monitors over screaming from the audience. Each member of the group can have their own monitor mix which is guaranteed to be the same in every venue on the tour. Known as I.E.M.s or IEMs for short.

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.

INDUCTION LOOP
System which amplifies audio frequency currents (from a microphone over the stage) around a large loop of cable (around the auditorium) to generate a magnetic field which can be picked up by a hearing aid switched to the 'T' position.

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.

INSET
A small scene set inside a larger one.

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.

INTERCOM
Usually refers to microphone/headset communications equipment. Abbreviated to 'comms'. Also known as 'cans'.

INTERMISSION
See INTERVAL.

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.

INTERVAL
Break between sections of a performance. During a play, the interval is normally half way through a standard length performance (approx 1 hour each half) and is usually 15 or 20 minutes in duration. Known in the US as an INTERMISSION.

INTERVAL MUSIC
Music played in the foyer and/or auditorium during intervals. Most usually Vivaldi's Four Seasons.

INTONATION
The way in which words are emphasised during a speech.

INVENTORY
A numbered packing list which itemises all single pieces travelling on a tour; all cartons, flightcases, crates, baskets together with quantities and descriptions of contents. Extremely important if touring abroad to satisfy customs. Dimensions/weight/value may also require recording.

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.

IRON
See SAFETY CURTAIN.

ISIS
ADB software used on high-end ADB lighting desks. Uses a 32-bit operating system with a very short boot-up time.
ADB website

ISORA*
A plastic CYCLORAMA, used because of it's light transmission properties. When lit from behind, the source of light is not visible through the plastic, making complex silhouette work possible.
When used in conjunction with a BOUNCE cloth (light directed onto the bounce is reflected onto the rear of the isora) very smooth coverage is possible.

ITALIAN MASKING
See MASKING.

ITC
Independent Theatre Council (UK)
ITC website

JACK
1) Segmented audio connector. Mono Jacks have two connections - tip and sleeve, and are unbalanced. Stereo jacks have three connections - tip, ring and sleeve.
B-type jacks (also known as Bantam jacks) were originally designed for use in telephone exchanges and provide a high quality (and expensive) connection in jackfields.
A-type jacks are cheaper and more common, but more fragile. A type jacks are available in 2 sizes : quarter inch and eighth inch.
2) (US) A hinged brace. In the open position, it holds up a flat or other unit of scenery. A Tip Jack is a combinaton of a jack and castors so scenery can be supported or rolled. When it is in position, it is tipped to vertical. When rolling, it leans backwards.

JACKFIELD
An array of jack sockets ('jills'), providing connections to equipment/outlets etc. A patch panel.

JARDIN
French for Garden. See STAGE RIGHT.
Derivation of Court & Garden

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

JONES, INIGO / INIGO JONES
MORE SOON

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.

JUVENILE LEAD*
TO BE DEFINED

JUVES
Short for 'Juveniles' - child members of the company.

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.

KABUKI DROP
Method for dropping a cloth from a flying bar. It consists of a bar which attaches to a standard flying bar, and is able to spin around. The bar has prongs welded to it on which the drop is hung (drop has grommetted holes in the top which hook onto the prongs). Normally these prongs are above horizontal, so the drop stays hung. On cue, the pole is rotated so that the prongs point downwards, and the drop consequently falls.

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.

KIRBY WIRE
Wire used to fly an actor.
Named after George Kirby, who devised the first pendulum artiste flying system (in 1898). His company Kirby's Flying Ballet is still supplying flying equipment now.
See also FLYING HARNESS.
Kirby Flying - History page

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.

KLEIN BAG
A canvas tool bucket originally designed for 'utility' contractors in the US, stout canvas with a rope handle and plastic or leather base. Ideally suited to and adopted for collecting hoist chain. Available as strong and large enough for up to 30m lengths of 7mm / 5/16' hoist chain.
Submitted by Chris Higgs

KLEIN TOOL
Klein Tools Inc. have been making tools since 1857, the 'tool' referred to is a generic term for two items, the 'Chicago' or 'Haven' grip, which are self gripping wire rope pulling tools, useful for tensioning catenary wires and general wire rope gripping jobs in rigging.
Submitted by Chris Higgs

KOTHURNOS
(Greek) High shoes worn by tragic actors to increase their stature.

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

LATENCY
In digital live sound systems there are tiny time delays due to the processing time required to convert sound from analogue to digital and back again. This time period is known as the LATENCY of the system.

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.

LAUAN (US)
A three layer plywood made from coarse grained tropical woods. Suitable for backing, filler or light duty bracing; not suitable for structural uses or where a smooth paintable finish is desired. Also known as Phillipine Mahogany.

LAVALIER MICROPHONE
Originally, a mic worn around the neck on a string. Now applies to a small 'tieclip' microphone. These microphones are used for TV and also in musical productions requiring the amplification to be 'invisible'. The mic is worn in clothing, in hair / wigs, over the ear or on the face (heavily made-up).

LAY
The direction and angle in which strands are 'twisted' in rope making) which in turn determines the 'hardness' of the lay (flexibility) in fibre ropes and the 'pitch' (frequency with which a strand appears when viewed along one side) of any rope.
Submitted by Chris Higgs

LCD / L.C.D.
Liquid Crystal Display. LCD displays are in use on electrical and electronic equipment across the world, and LCD technology is also used in video projectors.
See also TFT.
How LCDs work

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

LEADER TAPE
Non-magnetic plastic tape used to begin and end sound tapes and to separate cues on tape. Clear leader tape is used to activate the automatic stop on some playback machines. Leader tape is available in a variety of colours.

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

LEG
1) Each sling used as part of a multiple sling, e.g. a 'two leg sling' has two slings used as the 'legs' of the sling. A bridle 'leg' is therefore one half of a two 'leg' bridle, or one third of a three way bridle, etc.
2) See LEGS.
Submitted by Chris Higgs

LEGIT VOICE
Singing term - refers to a classically trained voice (see also BELT VOICE)

LEGITIMATE THEATRE
US term. TO BE DEFINED.

LEGS
Drape set as masking piece at the side of the acting area. Usually set up in pairs across the stage and used in conjunction with borders to frame the audiences view. One of many possible origins of the phrase 'Break a Leg', meaning to take an extra encore from the legs after a successful performance.
More information on Break A Leg

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

LEMO
A small metal multipin connector used for connecting radio microphone heads into the transmitter pack.

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

LEVEL
TO BE DEFINED

LIBRETTO
Text of an opera, or other long musical vocal composition. The script of a musical.

LICENCE*
TO BE DEFINED

LIFT
The orchestra pit and/or sections of the stage may be mounted on lifts to make moving of heavy items (e.g. piano etc.) easier. Sometimes the forestage doubles as the orchestra pit by use of a lift.

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 DESIGNER
Member of the production team for a show who is responsible for the overall look of the lighting. He or she may have an Assistant Lighting Designer who concentrates on the necessary paperwork for the lighting design. The Lighting Designer (or LD) is responsible for liaising with the director about style and with the set and costume designers about colour and decides on the position, type, focus direction and colour of every lighting instrument in the rig. He draws a lighting plan to communicate this to other members of his team (and to the theatre staff who are rigging the lighting). During a lighting plot, the lighting states are built.

LIGHTING DIRECTOR
A lighting designer for television is known as a lighting director.

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.

LIMITER
See COMPRESSOR.

LINE
A rope length, once cut to length or installed for a specific function. (To cut a line from a coil of rope)
Submitted by Chris Higgs

LINE LEVEL SIGNAL
Standard' level at which the inputs and outputs of domestic and professional sound equipment operate. Slight variations are that some equipment works at +4dB, some at -10dB. See MIC LEVEL SIGNAL.

LINE-UP TONE
Signal of known frequency and level used for setting up sound recording equipment levels accurately.

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 IN
See GET IN.

LOAD LAMP
See GHOST LOAD.

LOAD STRAP
See RATCHET STRAP.

LOADING BAY
Access into the theatre for scenery and other equipment. Also called the Get In.

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

LOGE
(esp.US) Seating area in traditional proscenium arch venues. Exact location varies according to the venue, but is usually a 'box' position at the dress circle level. (From the French Logè)

LOLER*
TO BE DEFINED

LORT
(US) League Of Resident Theatres. It is an agreement with Actor's Equity regarding payment/treatment of actors. Prior to this agreement, Equity basically dealt with Broadway type productions and nothing else.

LOUDSPEAKER
Device for converting the electrical signal from an amplifier back into sound waves, most commonly by vibrating a paper cone. Most speaker systems are composed of a number of sources - each designed to handle a specific range of frequencies. See Tweeters and Woofers, Bi-Amplification.

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.

LUAN (US)
See LAUAN.

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.

LUMINANCE
TO BE DEFINED.

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.

LYRICIST
Author of the text of a musical / the words of a song.
See also DRAMATIST.

M.U. / MU
M.U. is short for Musicians Union (UK).
Musicians Union website

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

MACBETH
See Superstition.

MAGIC SHEET
See CHEAT SHEET.

MAHL-STICK
A short stick used by scenic painters to steady the hand by resting its padded end against the surface being painted.

MAINTAINED LIGHTING
See Secondary lighting.

MAKE-UP
Products applied to the face or body of an actor to change or enhance their appearance. See also GREASEPAINT.

MAKING THE NUT
The 'nut' is a break-even point, after which the show can pay it's bills. It's calculated either show by show or for the length of the production (some costly shows don't make their 'nut' until well into the run). The origin of the term is believed to be 'to survive, a squirrel has to find at least a nut a day. For a person to survive, they must make at least $xx a day -this dollar figure is their 'nut'.'

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.

MARIE TEMPEST HINGE
Door hinge that has been reinforced by a screw lever to keep the door from opening by itself on a raked stage. Named after the actress Dame Marie Tempest (1864 - 1942).

MARKETING DEPARTMENT
See PUBLIC RELATIONS.

MARKING OUT
Sticking tapes to the floor of the rehearsal space to indicate the groundplan of the scenery. Also for marking position of furniture etc. within a set. Always be aware that some tapes may damage or mark some wooden floor surfaces!

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.

MASKING FLAT

MASKING TAPE
Paper sticky tape used to mark out the boundary of a surface to be painted or sprayed.

MASKING*
Neutral material or designed scenery which defines the performance area and conceals the technical areas. (e.g. Masking flat).
German Masking consists of 3 sets of flats or drapes lining the edges of the performance space (ie the 2 sides at 90° to the proscenium arch, and the rear of the space masked parallel to the pros. opening.) This type of masking is sometimes known as 'Up and Down Masking' as it runs up- and down-stage. This term seems to be rarely used now.
Italian Masking to be defined.

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.

MATINÉE / MATINEE
Afternoon performance of a show. (From the Latin for 'of the morning', but who does theatre in the morning?)

MATRIX OUTPUT
Set of outputs on a mixing desk which allows the user to preset a number of output configurations. eg on a 8 x 8 matrix, each of the 8 group outputs from the channels can be routed to any or all of the matrix outputs.

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.

MD
1) See MUSICAL DIRECTOR.
2) Mini Disc. See DIGITAL RECORDING.

MDF / M.D.F.
Medium Density Fibreboard. Dust masks must be used when cutting MDF, as the resins used for binding the board can be dangerous.

MEAA / M.E.A.A.
Media, Entertainment and Arts Alliance (Australia). Union & professional organisation covering the media, entertainment industry, arts industry and sport in Australia. An amalgamation of actors and technicians unions and professional bodies.
MEAA website

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

MECHANE
(Greek) Crane that lifted the DEUS EX MACHINA above the Greek stage.

MELODRAMA*
TO BE DEFINED

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

MIC
(pronounced 'Mike') Abbreviation for microphone.

MIC LEVEL SIGNAL
Low level audio signal produced by circuitry in microphone. Needs boosting either by a pre-amp or a mixing desk before it can be amplified. Susceptible to interference over long cable runs.

MICROPHONE
Device for converting sound into electrical pulses which can then be amplified or recorded onto tape. Signals from a microphone are very low level and are amplified in the mixing desk to line level. See Dynamic Mic, Condenser Mic, Phantom Power, Pick-up, Radio Mic.

MICROPHONE CAPSULE
An interchangable microphone head that fits onto a pre-amplifier. Many capsule types are available, all of which fit the same pre-amplifier.

MIDI
Musical Instrument Digital Interface. Control system established in 1984 for linking musical instruments or other electronic equipment and computers together and storing the control signals the equipment produces for subsequent playback. See MSC, MMC, SYSTEM EXCLUSIVE.

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

MIME
Form of performance with no spoken words. Plot, character etc. are conveyed to the audience by movement and gesture. From the Greek Mimos.
Marcel Marceau Foundation for the Advancement of the Art of Mime
Mummenschanz

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.

MINI DISC
See DIGITAL RECORDING.

MINI-DV / MINI DV
High quality domestic camcorder digital video format. See also DV.

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

MIRACLE PLAY
TO BE DEFINED

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.

MISE EN SCÉNE
TO BE DEFINED.

MIXDOWN
The process during which a multitrack recording is balanced and transferred to two tracks (stereo) for playback or reproduction.

MIXER
A desk comprising a number of input channels where each sound source is provided with its own control channel through which sound signals are routed into two or more outputs. Many mixing desks can also change the quality of the sound (see EQUALISATION).
A Powered Mixer has an amplifier built into it. Sound sources of varying levels are accepted which can be amplified if necessary.
Also known as a Sound Desk or Sound Board. (See Line Level, Gain).

ML
Short for MOVING LIGHTS.

MMC
MIDI Machine Control. A variation of the MIDI language designed for controlling mechanical equipment (eg Tape Players).

MODEL
A scale model provided by the set designer to help all the technical departments to co-ordinate and plan a production. Used as a reference when building, painting, dressing and lighting the set. The first stage of model-making is the WHITE CARD model which shows the form of the set, but not the detail of painting / texture / colour. When that's been approved by the director, and has been roughly budgeted, the final model is produced which should look identical to the finished set on stage. This is used as a reference by scenic artists and lighting designer etc.

MODELBOX
1) A wooden box representing the walls of a theatre space in which cardboard scale models can be placed by the set designer. See also MODEL.
2) UK-based CAD in Theatre specialist. Lighting symbols for CAD programs are available as a free download.
Modelbox website

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.

MONKEY POLE
A stick threaded at one end with the line used to cleat two adjacent flats together, enabling the flats to be quickly and silently joined or separated. The stick remains attached to the line and flat of which it forms part.

MONOLOGUE*
A speech within a play delivered by a single actor alone on stage. See also SOLILOQUY.

MONOPHONIC (MONO)
Single channel sound recording, as opposed to STEREOPHONIC, which uses two channels (left and right).

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.

MORALITY PLAY*
TO BE DEFINED

MOTION CAPTURE
A technique from the film special effects and video game industry which enables a video artist or choreographer to 'capture' the movements of an actor or dancer digitally so that those movements can be reproduced by a virtual actor or dancer that's been computer-generated.
DanceTech Motion Capture page

MOTOR
Generic term for an electric chain hoist. (Rumoured to have been started by an enquiry as to whether 'CM' stood for 'chain motor').
Submitted by Chris Higgs

MOTOR-UP
Term used when a self climbing motor is rigged conventionally, i.e motor up. Motor down is sometimes used to convey the opposite, but in general it is understood that all motors 'climb'.
Submitted by Chris Higgs

MOUSE
Moving part of a scenic automation system. Mice run on cables under the stage floor, and can be made useful by inserting a metal SPADE through a wheeled piece of scenery into the mouse, which then pushes or pulls the scenery with it. The scenery sometimes has additional guide pins which move in guide tracks which allow the scenic piece to move in more complex directions.

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:

MOVING MIRROR
See MOVING LIGHT.

MR SANDS
Often used as a code word for fire over a public address system (e.g. 'Mr Sands is in the foyer' means there's a fire in the foyer). Many theatres have their own code words.

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

MS
MS stands for Mid and Side. It involves the use of two different types of microphone capsule - a cardioid for the M and a figure-eight for the S. The biggest advantage is that centre sounds are not 45 degrees off-axis as with XY, because the Mid capsule points along the centre-line. This means that there isn't so much of a 'hole' in the centre of the stereo image. The Side capsule is placed at right angles to the M capsule. The M is connected to a mixer channel. The S is split into two and connected to two mixer inputs. The M is panned centre. One of the S inputs must be phase-inverted. Find out which is the left and which is the right and pan hard left and hard right respectively. If set correctly, there will be no noise if the M is switched off because the two S channels cancel each other. Originally, there were problems with reflections and due to the use of two different capsules, although single-point MS mics have been developed which overcome the problem quite effectively.

MSC
MIDI Show Control. A control language which is an extended version of the original MIDI language. In addition to a 'go' command, cue numbers and other information can be sent as well (in addition to fault reports and safety checks).

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

MUMMERS PLAY*
TO BE DEFINED

MUSICAL DIRECTOR
Often the conductor/leader of a musical, or the person responsible for the musical content of a production. Also known as the MD.

MYSTERY PLAY*
TO BE DEFINED

NAB
National American Broadcast. Standard for tape recording equalisation characteristics.

NAGRA
A portable audio reel-to-reel tape recorder, manufactured by Kudelski in Switzerland. The analogue Nagra was the industry standard for radio & TV reporters and for film location sound. The company now manufacture digital recorders to the same rugged build quality.
Nagra website

NATURALISM*
1) When creating a lighting design, naturalism dictates that lanterns should be placed according to where the light would come from in nature. For example, a sunny day would be lit primarily from above the acting area, with fill lighting in from the sides as if from the cloud. A dark room would be lit by moonlight through a window, and the light level would increase when a door is opened from a lit corridor or when a light fitting is turned on.
2) Naturalism in performance: TO BE DEFINED.
3) Naturalism in scenic design: TO BE DEFINED.

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).

NICAM
TO BE DEFINED.

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

NODE
The connection between structural members in a construction (from Latin, a knot).
Submitted by Chris Higgs

NOISE BOY
Theatre or concert sound engineer. Normally male. But not exclusively so! Also known as a Hum Head. See also Techie and Lampy.

NOISE GATE
A piece of sound processing equipment that reduces background noise by muting a sound signal when it falls below a certain level, restoring it when the level increases again. Must be used on vocal microphones with care, because it may cut the signal off, although the vocalist is still singing quietly. Also known as an Expander.

NOISES OFF
Stage direction to indicate a clatter / bang offstage to which the cast should react. The type of noise should be indicated by the surrounding action!
Also, a farce by British playwright Michael Frayn about life backstage, featuring a large interval set change.

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.

NORMALLING*
TO BE DEFINED

NOTES
Following a rehearsal (or an early performance in a run) the director will give notes to the cast and crew about where to make changes, improvements, cuts etc.

NTSC
North American Television Standards Committee. TV standard in the USA.
More about TV standards

O.P.
Opposite Prompt side of the stage. Stage Right. (ie Actors right when facing audience).

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.

OFFLINE EDITING
TO BE DEFINED.

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.

OISTAT
International Organisation of Theatre Scenographers, Technicians and Architects.
OISTAT website

OLEO CLOTH

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

OMNIDIRECTIONAL
See PICK-UP.

ON THE BOOK
1) An actor who needs to refer to the script during a scene is said to be 'on book'. The ideal situation is for the actor to be 'off book' as quickly as possible!.
2) See PROMPT BOOK.

ONKOS
(Greek) Section above the face of a mask rising to the top of the head.

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

OPEN THE HOUSE
Clearance given to FOH staff by stage management that the stage is set and the audience can begin to take their seats. When this clearance is given, the backstage call 'The House is now open, please do not cross the stage' is made.

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

OPENSTAGES
Powerful visualisation software for students and scenic designers. Doesn't have the engineering accuracy of Autocad or the lighting simulation of WYSIWYG but is much more geared towards theatre, and is much easier to learn.
Openstages website

OPERA
1) European terminology meaning Opera House - lavishly decorated proscenium theatre with orchestra pit. See TOSCA.
2) Musical form. Highly dramatic and stylised form where the text is completely sung.

OPTICAL FIBRE
See FIBRE OPTICS.

ORCHESTRA
1) In Greek Theatres, the central performance area used by the Chorus or for dancing.
2) Refers to the main seating area of the auditorium at floor level.
3) Colloquially known as 'the band' the musicians who perform from the orchestra PIT.

ORCHESTRA PIT
See PIT.

OUT
In flying, means up (out of sight).

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

OVERHEADS
1) Microphones positioned above a drum kit to pick up the cymbals etc. without getting hit.
2) Microphones positioned over the stage to pick up the overall sound of the concert / production.

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.

OVERTURE
Introductory musical piece played before a musical which contains many of the musical motifs and themes of the score.

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.

PA SYSTEM
Short for Public Address System.

PACK
See RADIO MIC.

PAD
A switch on a mixing desk input channel which attenuates (reduces the level of) a signal. Used if a loud / high level signal is causing the desk to be overloaded.

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

PAGING
The act of holding a tab etc. back to allow large items or actors offstage. Also preventing microphone etc cables from getting entangled by pulling / releasing them from offstage as performer walks around.

PAINT FRAME
Large vertical wooden frame from which cloths are hung for painting. The frame is often winchable for easy access.

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

PAL
Phase Alternate Line. TV standard in the UK and Europe.
More about TV standards

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.

PANTOMIME*
TO BE DEFINED

PAPER TECH
See TECHNICAL REHEARSAL.

PAPER THE HOUSE
Marketing technique. Giving away tickets to a performance (eg Opening Night) to make a show seem to be selling better than it actually is, and to start generating 'word of mouth' interest.

PAPIER MACHE

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.

PARADOS
(Greek) Alleyway between the SKENE and the ORCHESTRA for the CHORUS to use as entrances.

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.

PARALLEL MONOLOGUE
TO BE DEFINED

PARAMETRIC EQUALISER
Equalisation control where the range of frequencies to be boosted or cut can be selected. Allows the 'fine-tuning' of the equalisation.

PARASKENE
(Greek) Towers at each side of the SKENE building.

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

PASS DOOR
A fire-resisting door in the wall of the proscenium arch which is the only correct access between the auditorium and the stage.

PASSARELLE
A walkway leading beyond the proscenium arch around the audience side of the orchestra pit. Enables actors to get very close to the audience, and often used in musical theatre or cabaret performances. There are problems with sound reinforcement (feedback is much more likely due to being closer to the front of speakers) and video relays are often used as the conductor is no longer visible.
PASSERELLE means Footbridge or gangway in French.

PASSIVE
Opposite of ACTIVE. See ACTIVE.

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 BAY
See PATCH.

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

PCC
Phase Coherent Cardoid. See BOUNDARY MICROPHONE.

PD's (Per Diem)
A daily payment by an employer to touring technicians to cover daily living expenses. This is additional to the monthly / weekly wage.

PEACOCK
See SUPERSTITION.

PEARL
A domestic lamp which has a frosted finish to diffuse and soften the light.

PEAVEY
(Manufacturer) American manufacturer of amplifiers, sound processing equipment, and musical instruments.
Peavey website

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

PER DIEMS
See PDs.

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.

PERIAKTOI
(Greek) Term for three-sided flats mounted on a rotating base. Used in rows to produce easily changed backings.

PERSONAL PROPS
See PROPS.

PFL
See PRE-FADE LISTEN.