Lighting control

Two lighting consoles in the dark

Light designer at a grandMA 2 light console

Light control is the generic term for control devices for lighting systems in event technology . These differ greatly depending on the area of application. In general, there are four types of lighting controls:

Generic consoles: Consoles that are designed purely to control conventional light.
MovingLight consoles: Consoles that are designed purely to control intelligent light.
Hybrid consoles: Consoles that are able to control a mixed setup of conventional and intelligent light
Interfaces: which are usually connected to a PC or laptop via USB (formerly ISA / PCI plug-in cards) and can control both conventional and intelligent light (depending on the software and interface used)

Basic terms

Presets

A preset is the option of setting a second one on the desk while a light scene is being output, so that the scene can be switched over to the other immediately after the scene has ended. In order to make this possible, there must be at least two controllers for each channel on analog consoles. Usually these are arranged in two rows one below the other. The first row is then for the first, the second for the second preset. One or two faders are used to fade between the two presets.

In the case of moving light controllers or hybrid consoles, the term preset or palette also denotes a “preset”, but channel values are saved here in order to then create the final lighting moods from the individual presets using a modular system. This has the advantage that when a preset is updated, these changes are automatically adopted in the lighting scenes in which the preset was saved.

Scenes / cues

A cue is a light scene, usually called a light mood in the theater. A cue stores which channels are to be controlled with which value. So z. B. comfortably define and save the respective color components of a scene. During a performance, the individual channel controls do not have to be set, but just a cue that outputs the complete light scene at once.

Other commonly used names for cue are “memory” or “scene”, depending on the manufacturer.

Originally, “cue” is the name for the keyword or the use that initiates a scene (from English “cue” = keyword, call).

sequence

A sequence (also known as a “chaser”) is a series of fixed values for certain channels. Sequences can be used to chase - to program and flashing effects.
If a lighting desk distinguishes between chaser and sequence, the chaser usually designates a constantly clocked sequence of lighting moods, while in the sequence each individual mood has its own idle and fade time.

Stack (cuelist)

A stack is a series of CUEs and / or sequences. They are used to switch from one CUE to the next in defined program sequences (e.g. theater). Stacks can also contain information about fading from one mood to the next. If a stack has been programmed, the lighting technician only has to switch to the stack at the right time during the performance, which is done by pressing a button.

Some manufacturers also refer to such a stack as a "sequence" or cue list and the above. Sequence as a "chaser". There is no clear definition here, as the various manufacturers only adhere to a uniform nomenclature to a limited extent .

Desk concepts

Preset consoles

Preset consoles are the most original form of lighting control. Brightness values are set for each channel using faders . Most of these consoles have two presets, flash buttons, master control and possibly a circuit for fading with adjustable speed. Consoles of this type usually have analog outputs (e.g. 0–10 V). One of the best-known products is the Lightcommander.

Scene desks

In contrast to the preset consoles, consoles with a scene memory require a microcontroller for control and therefore usually output a DMX signal instead of 0–10 V signals . The function of the presets is taken over by the scenes. A lighting mood is set using the faders and stored in the console's memory. In operating mode, this mood can then be called up again using a fader. Many consoles offer a preset mode in addition to this operating mode. In addition, sequences (some controllable by music) are often offered.

Theater desks

Theater consoles are elaborately designed consoles for conventional and moving light and other DMX-controlled devices, such as fog machines, laptops for projector image projections, color scrollers, stage podiums, etc. Usually they are equipped with several control monitors to monitor the intensities of the individual light circles as well as to be able to display light levels or functions of moving lights to be edited.

Several options for lighting control are offered:

Submaster control : Several DMX channels can be combined on a fader with their previously programmed value. When using several submasters, lighting moods can be changed actively, intuitively and individually at any time without programming.

Group control : Several DMX channels are combined with their programmed value into a group and can thus be used for further programming (shortening of syntax command lines).

Scene control : programmed light levels, effects, chasers and movements can be run using the Go button

Network-compatible lighting controls are being used more and more frequently in theaters. This makes it possible to use a PDA or laptop to control the lighting desk, dimmer systems and even moving heads via W-LAN. This is advantageous if, for. B. due to a lack of space, the desk cannot be set up in the auditorium with a view of the stage during the performance. During rehearsals, lighting moods can be set and saved using the convenient operating options of the "large" lighting desk. For the event, the saved show is simply loaded onto the laptop or PDA and “driven” from this device. A network architecture also allows a redundant backup system with a second lighting desk as an emergency desk, which takes over the lighting control if the main desk fails.

Conventional theater desks are programmed and controlled using syntax commands. Example: Strand Lighting 530i

233 @ 55 "Enter" Sets the dimmer channel 233 to 55%

100 @fixture 12 "Enter" Automatically sets device 12 with all functions such as PAN / TILT / GOBO / IRIS ... from a device list on DMX channel 100 (and any subsequent DMX channels that may be required) and then locks them for others use

Desks for intelligent light

The control of scanners and other intelligent light is not sensible with the aforementioned consoles, so separate consoles are often used. Here the devices to be controlled are first programmed in to take into account the assignment of the channels. The mirror / head positions are programmed and combined in sequences. Depending on the console, individual or multiple sequences can then be run at the same time. Often parameters such as color , gobo and speed can also be changed during runtime. Many consoles of this type are also able to control conventional light to a limited extent.

Hybrid consoles

Hybrid consoles, also called hybrid consoles, combine the functions of theater consoles and consoles for intelligent light. Because of the effort involved, PCs with special hardware are usually used. These are consoles that are used at corresponding show sizes, e.g. B. in stationary musicals, TV shows and large theaters. Due to the large number of channels, these consoles often offer several DMX universes or network protocols (ArtNet, Pathport) to control several thousand channels. The most famous hybrid consoles include the grandMA series and the dot2 consoles from MA-Lighting, the Hog series from High-End Systems, the ChamSys consoles and, for smaller productions, the Licon consoles from JB-Lighting.

Interfaces

The corresponding interface is usually connected to the desktop / laptop via USB and then converts the USB signals into DMX signals . When USB was not yet very widespread, ISA or PCI plug-in cards were also offered. Since most PCs / laptops now have USB, new interfaces can usually only be purchased with USB. A corresponding software offers the possibility of programming and control, sometimes with a lot of functions that often only come with very expensive desks ( macros etc.). Often it is also possible to control the software via external sources, e.g. B. MIDI .

literature

Michael Ebner: Lighting technology for stage and disco. A handbook for practitioners. Elektor-Verlag, Aachen 2001, ISBN 3-89576-108-7 .