AV glossary

Video and screens first, because that is what most quotes argue about. Audio, lighting, staging, rigging and power follow.

• Confidence monitor A screen facing the stage rather than the audience, showing the presenter their own slides so they never have to turn around.
• Fast-fold screen A large projection screen on a folding frame that assembles on site, dressed with skirting and available for front or rear projection.
• IMAG (image magnification) Live camera feed of whoever is on stage, put up on the screens so the back of the room can see a face instead of a distant figure.
• LED panel (cabinet) The individual module an LED wall is built from — typically 500mm square, hung or stacked in a grid, and the unit everything about a wall is counted in.
• LED wall A screen built from modular LED panels bolted together, bright enough to read in daylight and sized to the room rather than to a projector lens.
• Media server A purpose-built playback machine that drives screens reliably — the reason a show does not depend on somebody’s laptop not going to sleep.
• Pixel pitch The distance in millimetres between the centres of two adjacent LEDs — the number that decides how close your audience can sit, not how good the screen is.
• Projection mapping Projecting onto something that is not a flat white screen — a building, a set piece, a staircase — with the image built to fit that exact surface.
• Rear projection Projecting from behind the screen instead of in front of it, so nobody walks through the beam and no presenter is ever lit up by the projector.
• Teleprompter Scrolling script reflected onto angled glass so a speaker reads while looking straight ahead — at the audience, or down the barrel of a camera.
• Video switcher The device that decides which source the screens are showing at any given second, and the person operating it is as much of the specification as the box.