Glossary of Technical Theatre Terms – Theatrical Effects


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

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

COLOURED SMOKE
Pyro: Coloured Smoke (Le Maitre) Pyrotechnic device, produced by Le Maitre, which is available as a cartridge which plugs into a flash pot, and when detonated, produces an intense cloud of coloured smoke. Care must be taken as the smoke contains a pigment which can stain light coloured objects or costumes.

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.

EMERGENCY STOP
Also known as E-STOP, all scenic automation or powered flying systems have an emergency stop facility built into them. The pressing of any e-stop button in the system will immediately halt any movement and prevent any further movement until the system is reset.

FLASH BOX
Flash Pods for use with the Pyroflash system (Le Maitre) A small box containing the socket into which a pyro cartridge is plugged. Also known as a flash pod or firing pod.

FLASH POT
A generic term for a pyrotechnic device consisting of a small cylindrical container into which pyrotechnic powder has been loaded. At the bottom of the container is an electric match or igniter which, when a large enough electrical current flows through it, produces a spark which ignites the powder. Many companies (such as Le Maitre and Theatre Effects) produce cartridge flash pots which are pre-loaded and sealed, reducing the likelihood of incorrect usage.

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

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.

GERB
See PYROTECHNICS.

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.

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

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

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 19th century to simulate the sound of cannon, it was often used to call out the volunteer lifeboat crew in an emergency.

PERFORMER FLYING
A manual or electrically driven system for lifting performers off the stage and allowing spectacular stunts and aerial sequences to be performed.

PYROFLASH
Pyroflash System Controller (Le Maitre) A range of pyrotechnic cartridges, fliring pods and controllers used to create pyrotechnic effects in semi-professional situations.

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

SILVER JET
Pyro: Silver Jet (Le Maitre) Pyrotechnic cartridge produced by Le Maitre, which produces a bright shower of sparks in a fountain. This is a type of GERB.

SMOKE COOKIE
A pyrotechnic product which produces a cloud of real smoke when set alight.

THEATRICAL FLASH
Pyro: Theatrical Flash Large (Le Maitre) Pyrotechnic cartridge produced by Le Maitre, which produces a bright white flash, a small bang, and a large mushroom of smoke.

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

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