Education

The planning conversation before a show, settling technical needs, timings and logistics with the venue. · advancing

An interoperability standard that lets different networked audio systems exchange streams.

A way of carrying many DMX universes over a standard network instead of separate cables.

The shape of an image, width against height — 16:9 for most screens, far wider for many stage designs.

Light from behind a subject, separating them from the background. · hair light, rim light

Everything the audience does not see — dressing rooms, crew catering, storage, corridors. · BOH

A cabling scheme that carries a signal twice, in opposite polarity, so interference picked up along the run cancels out.

The second in charge of a lighting or grip department, running the crew and the gear list.

How finely each sample or pixel value is measured — more bits means smoother gradients and quieter noise floors.

All light killed at once, usually to hide a change or end a moment. · BO

Overlapping two projectors so their images join into one, with the overlap faded to hide the seam. · edge blend, soft edge

Two legs of steel from separate points, meeting at one hanging position when nothing is directly above it.

A short, sharp change — a lighting state that snaps rather than fades, or an audio hit between segments.

The daily sheet telling each crew member where to be, when, and doing what.

The time a person is due on site, ready to work — not the time they arrive at the car park.

The single-pole connectors used for heavy power feeds, one per conductor. · cam-lok

The motor that lifts truss and scenery into position, and holds it there. · motor, chain motor

The scheme used to compress and decompress media — the trade between file size, quality and processing cost.

How warm or cool a white light looks, in kelvin — 3200K is warm tungsten, 5600K is daylight. · color temperature, kelvin

The crew intercom system — headsets and belt packs that let departments talk during a show. · intercom, talkback

A screen facing the stage so a presenter can see their slides or notes without turning round. · comfort monitor, downstage monitor

Colour rendering index: how faithfully a light source shows colour compared with daylight. · colour rendering index

A stored state — of lights, sound, video or stage — recalled at a point in the show.

The ordered list of cues an operator steps through as the show runs. · playback

A large seamless backdrop, usually lit as a background colour or sky. · cyc

A widely used system for carrying many channels of audio over a standard network cable.

A period when the venue is closed and no work happens — often overnight between build days. · dark day

Hanging something on fixed steel rather than a motor, so it cannot be moved once it is up. · dead hang

A stage platform section, or the stage floor as a whole. · staging, riser

A box that converts an instrument-level signal into a balanced microphone-level one the desk can take over a long cable. · direct box

The distribution unit that takes one large supply and splits it into the many outlets a show needs. · power distribution, distribution

The control protocol lighting runs on: 512 channels of instructions per universe, sent down a single cable. · DMX

Towards the audience. Upstage is away from them. · upstage

A softer light opposite the key, lifting the shadows it leaves.

To lift scenery, lighting or drapes out of view above the stage. · flying, fly system

A manually operated spotlight that tracks a performer around the stage. · followspot

How many images a second a video carries — 25, 30, 50 and 60 are all common, and mixing them causes judder. · fps

The audience side of a venue — and the mix position out in the room where sound and lighting are operated. · FOH

On film and television, the head of the lighting department.

How much level a microphone can be pushed to before it starts to ring or howl.

Setting levels correctly at each stage of a signal chain so the result is loud enough without distorting. · gain staging

A shared timing reference that keeps every video device in a system in step, so sources can be cut between cleanly. · sync, black burst

A generator, brought in where venue power is absent or insufficient. · generator

A cut or etched pattern placed in a light to project a shape — a window, a texture, a logo. · template, pattern

The room where performers and speakers wait before going on.

The department that rigs and moves everything supporting the camera and lights — stands, track, flags, mounts.

A fine atmospheric mist that makes light beams visible in the air. · atmospherics

The consumer video connector, common on laptops and playback devices, but limited over distance.

Image magnification: live camera feeds of what is happening on stage, shown on screens so the back of the room can see. · image magnification

Earpieces that give a performer their monitor mix directly, instead of speakers on stage. · IEMs, in-ears

The main light on a subject, setting the exposure and the direction the shot is lit from.

The trapezoid distortion when a projector is not square to the screen, and the correction that squares it up.

The delay between something happening and it arriving — audible as lip-sync error when audio and video drift apart.

A column of loudspeaker boxes flown together so their output behaves as one tall source, covering a room evenly.

A quick pass confirming every input is arriving at the desk on the right channel — shorter than a soundcheck.

Audio and picture arriving together, so a speaker's voice matches their mouth. · av sync

Getting the show into the venue and built — trucks unloaded, rigging up, gear placed and powered. · bump-in, get-in

The reverse of load-in: striking the show and packing the trucks, usually against the clock. · bump-out, get-out, strike

A measure of a projector's light output. The brighter the room, the more you need. · ansi lumens

Tape on the floor showing exactly where people and gear go, so a set can be rebuilt identically. · spike marks, spiking

A computer that plays back and manipulates video content in real time, feeding screens or projectors.

The mix sent back to performers so they can hear themselves — separate from what the audience hears. · foldback, wedge mix

A fixture whose head pans and tilts under control, so its beam can be repointed during a show. · mover, intelligent fixture

A thick cable bundling many audio lines in one run between stage and mix position. · snake, loom

One screen split into many small feeds, so an operator can watch every source at once. · multi-viewer

A way of sending video between devices over a standard network instead of dedicated video cable.

The map between control channels and the physical fixtures or circuits they drive.

DC power sent up a microphone cable to run a condenser microphone or an active DI box. · 48 volt

The distance in millimetres between the centres of two LED pixels — the smaller the number, the closer you can stand.

The drawing showing every fixture in the rig: what it is, where it hangs, and where it points. · lighting plot, light plot

Power over Ethernet: running a device's power down the same cable as its data. · power over ethernet

A single fixing in the roof from which something is hung, and the load it is rated to take. · rigging point, hang point

The day-by-day plan for the whole job, from load-in through rehearsals, show days and load-out.

The finished mix of the show, as sent to broadcast, recording or overflow rooms. · PGM

Precision Time Protocol: the clock that keeps networked audio and video devices in step, to the microsecond. · IEEE 1588

A protective device that cuts power the instant current leaks to earth. Called a GFCI in North America. · GFCI, ELCB

A second path or second device ready to take over the instant the first fails. · backup, failover

The pixel dimensions of an image — 1920x1080 (HD) and 3840x2160 (UHD) being the usual reference points.

A video feed sent back to a source or a remote site, showing what is going out. · reverse feed

The document an artist or act attaches to a contract, listing technical and hospitality requirements. · tech rider

Pushing a system until problem frequencies ring, then cutting them, so microphones can run louder without feedback. · ringing out

A raised platform on stage — for a drum kit, a band, a panel of speakers.

The crew member who fetches, carries and drives, keeping departments supplied through the day. · PA, production assistant

The minute-by-minute script of an event: every cue, who calls it, and when it happens. · ROS, show flow, cue sheet

Streaming ACN — the other common standard for sending lighting control over a network. · E1.31

A device that converts an incoming signal to the resolution and rate a screen or switcher needs. · processor

Serial digital interface: the coaxial video connection professional gear uses, good over long cable runs. · serial digital interface

The rated metal link that joins rigging hardware together.

Mains power supplied by the venue, as opposed to a generator brought in. · house power

The person who calls the cues live, keeping every department in step with the run of show. · caller, stage manager

What an audience member can actually see from a given seat — and what the set must stay clear of. · sightline

The fabric elements of a set: drapes, legs, borders, cycloramas and masking. · drapes, masking

Setting and rehearsing levels and mixes with the performers before doors open.

The unsupported distance between two points holding a truss — the number that decides how much can hang from it. · truss span

A hard-edged fixture that produces a defined beam, usually able to project a gobo. · profile

The SMPTE standard for carrying video, audio and data as separate streams over IP networks. · SMPTE 2110, 2110

The input panel on stage that gathers microphone and instrument lines and sends them to the desk. · snake head

Left as the performer faces the audience — the audience's right. · SL, house right

The device that cuts between video sources and builds the picture that goes out. · vision mixer

Safe working load: the most a piece of rigging equipment may be asked to carry. · safe working load, WLL

The light showing which camera is live on air, so operators and talent know where to look.

A common crewing agreement that a working day is ten hours before overtime begins.

A power supply carrying three live conductors, letting a big load be split evenly across them. · 3 phase

How far a projector sits from the surface it fills — set by the lens and the image size required.

A running clock embedded in audio or video so separate systems can be locked to the same position. · SMPTE timecode, LTC

The aluminium framework lights, screens and speakers hang from.

The rest period between a crew member finishing one day and starting the next.

One set of 512 DMX channels. A rig bigger than that is split across several universes.

A logical split of one physical network into separate ones, so lighting, audio and video traffic stay apart.

A soft, wide light covering an area evenly, as opposed to a tight beam.

A floor monitor speaker angled up at a performer from the stage deck. · floor monitor

The offstage space at the sides where performers wait and crew work, out of sight.

The three-pin locking connector used for balanced audio — the standard microphone cable end.