Glossary of technical terms
FRENSNEL- Also called a wash light. The fresnel is a good general lantern. It produces a light with soft edges and this means that a number of fresnels can be used together to evenly cover a whole stage with light.
PROFILE- Profiles create a defined beam of light that is useful as a spotlight for an actor, or to pick out details on a set. They are usually long, thin lanterns. Profiles are also good lanterns for gobos. Attached to the front of the profile is a gate where the gobo or gel can be placed. this can be shaped using shutters.
GELS- A sheet of coloured gel (originally gelatine, and now heat-resistant plastic) is placed in a colour frame in the colour runners at the front of a stage lighting instrument.This is a commonly used method for ensuring the lighting state looks interesting and natural. Having a single colour washing the whole stage can look flat, and can use a lot of lanterns.
GOBOS- Go between optics can be used to create shapes with light. These are metal frames that are placed in front of a light source. The frames have shapes cut into them, so that when the lantern is on, the outline of the shape can be seen on the stage floor or wall. Gobos can be used to create the effect of trees, water, or moonlight, for example. Although professional gobos should be used with stage lanterns, you can experiment with gobo effects by cutting shapes out of cardboard and holding them in front of a torch.
BARN DOORS- These can be adjusted to change the shape of the beam of light on a frensnel to highlight particular areas.
DMX- DMX is an acronym for Digital Multiplex. It is the standard digital communication protocol that is used to remotely control intelligent lighting fixtures. The brains of the DMX is the controller (a desk, console or playback). The DMX controller broadcasts DMX in universes, a universe is 512 channels of DMX. DMX displays 0% - 100% as 0 - 255 however this has little impact over control of lights.
EN131- This is the safety code that all ladders in the UK are required to have in order to be used.
kVA- Kilovolt-amps is 1,000 volt amps. Its is a measurement of power.
SINGLE PURCHASE- single purchase as the lines just go from the bar to the grid, over one pupulley along the grid to one side over another pulley and then back down to the cradle, a line is then attached to the cradle that is just a loop that enables you to pull it in or out. the bar will move the same amount as the cradle and this will require you to have a counterweight system the full height of the fly tower.
DOUBLE PURCHASE- the cradle only moves half the distance the distance the bar does, very useful when you need to have a fire exit or something the wall that stops the counterweight cage brbeingble to reach the deck. double purchase woRks primarily the same way as single purchase but with the addition of an extra set of pulleys meaning that the distance travelled by the bar is double the distance travelled by the cradle. in double purchase you will also need double the weight in the cradle that is on the bar (and double that from single purchase of the same weight item)
SINGLE PHASE - single-phase electric power is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison.
THREE PHASE- Three-phase power can be defined as the common method of alternating current power generation, transmission, and distribution. It is a type of polyphase system, and is the most common method used by electric grids worldwide to transfer power.
CARDIOID- the polar pattern that a microphone is able to pick up, consisting of pick up points, null points and angles of acceptance.
SUPERCARDIOID- these have narrower angles of acceptance than regular cardioid patterns.
PROXIMITY EFFECT- the increase in bass frequencies as the source gets closer to a dynamic cardioid microphone (~ 16db increase ~100hz)
TRANSIENT- a transient is a high amplitude, short-duration sound at the beginning of a waveform.
SPL- sound pressure level
COMB FILTERING- In signal processing, a comb filter is a filter implemented by adding a delayed version of a signal to itself, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly spaced notches, giving the appearance of a comb.
SUB GROUP- A Subgroup is a mix bus destination where you can route channel outputs. The audio channels can be processed at that point with effects like EQ and Compression. The Subgroup fader will adjust the volume of channels that are routed to that group. The Subgroup master fader only affects the level going into the main mix and does not affect the level going into any other post fader mixes. Each mixer is going to be a little different in how many subgroups they may have.
VCA- stands for Voltage Controlled Amplifier. In a typical analog audio console, the audio signal actually travels through each channel fader. You could think of the fader as a rotary volume control stretched out flat. As you adjust the fader, it uses a resistive element to vary the strength of the audio signal on that channel.
DCA- (digital-controlled amplifier) works much like it sounds; instead of altering the actual signals from the channels, the signals are processed in the same way, which then leads to increased or decreased volume.
SOCAPEX-Socapex is a brand of electrical connectors, known in the entertainment industry primarily for their 19-pin electrical connectors, commonly known as Socapex connectors, and used in film, television, and stage lighting to terminate the ends of a multicable.
INTELLIGENT FIXTURE-Intelligent lighting refers to stage lighting that has automated or mechanical abilities beyond those of traditional, stationary illumination. For this reason, intelligent lighting is also known as automated lighting, moving lights, moving heads, or simply movers.
BREAKOUT- A connection at the end of a multicore cable which allows the connection of many items to it. (e.g. there is a breakout box at the end of a sound multicore cable which allows you to plug microphone cables into it).