Keying the stage lights fantastic

The Guardian (Manchester); 03 January 1991; Claire Neesham; p. 27

THIS year thousands of people will flock to London's West End to see shows like Children of Eden, Miss Saigon and the Rocky Horror Show. These theatre-goers have high expectations not only of the singing, dancing and content but also of the special effects produced with lighting and sound. Special effects are now an essential part of the West End blockbuster. Theatre production companies are under continuous pressure to come up with new ideas that will excite and astound today's sophisticated audiences. This pressure, along with the need to be cost effective, has prompted some theatre companies to turn to computers and programmers to achieve the effects they need. The most popular use of computers in the theatre is in processor-controlled lighting desks. Ian Albery, managing director of Donmar, a supplier of stage lighting, estimates that over 90 per cent of the UK's ``real'' theatres have some form of computerised lighting desk. He says theatres were swift to embrace this technology when it arrived in the 1970s when the rock musical was in vogue. Computerised desks appealed because they increased reliability, reduced operator costs and made complex lighting effects practical. Previously theatres had analogue desks with two or three rows of faders, each row having a fader per lighting channel. One row was ``live'' while the others were pre-set ready for the next cue by the operator. The faders controlled thyristor-based dimmers which altered the lighting levels of the lanterns. For most shows this system was a big improvement on its predecessor: a conventional organ with its knobs wired to clutches controlling the light dimmers (power cables dipped in salt water tanks). A top end Strand Grand Master Organ could have up to 10 operators using their hands, knees and feet to adjust the knobs. The fader system cut these operator costs and acrobatics. But lighting designers then started using 200 lighting channels in a show, and several operators were needed just to pre-set the faders between cues a process that was error prone and expensive. The computerised controller overcame all this. Today, the lighting team can store data for hundreds of channels and cues in memory, and carry the data for whole shows around on a 3.5in disc. Cues can be called up with the proverbial press of a button. As a result the Rocky Horror Show, which uses 250 channels and has over 130 cues, needs only one operator. The Rocky Horror Show, at the Piccadilly Theatre, has an ARRI Imagine 500 lighting desk a typical large computerised theatre lighting board. There are still two rows of 12 faders, but any light sequence set-up using them can be stored. Monitors are used to give feedback on which lights are being used and a display on the desk supplies the cue number. A keyboard is used for mass entry of light and cue data. One noticeable feature of the ARRI desk (and similar systems from suppliers such as Rank Strand) is that a lot of effort has been made to hide the fact that they contain computers. But such desks contain memory, a DMX chip for connecting the controller to several hundred digital dimmers, and a processor. The most popular is a Z80-compatible programmed-in assembler. But now Intel 80386/486 motherboards running a standard operating system such as Unix, and programs written in C are now being talked about. Even with this trend towards standard technology, Peter Ed, sales manager at ARRI Lighting, says that the user interface will stay simple. He believes that lighting desks should use the syntax of the user not the syntax of the computer. This is reflected in the ARRI design where the keyboard only has functions relevant to lighting so there are numbers and keys for functions like ``cue'' and ``at'' for specifying the light intensity. This layout allowed Paul Williams to key in The Rocky Horror Show's basic 130 cues in four hours, as they were dictated to him by the show's designer. The designer had drawn out the Rocky Horror lighting plan on paper. But a few designers are starting to use computer aided design for stage lighting. David Hersey who was responsible for the lighting of Children of Eden, Miss Saigon and many other major shows is one of this new breed. His team uses software which is like an architect's drawing package, but has special symbols for theatre use. The computer drawing is updated every time a change is made, and when appropriate the drawing can be plotted on to paper. The system also produces a printed cue list for the lighting desk operator to key in. Lighting desk manufacturers are already looking at the next step: the direct transfer of data from the PC or Macintosh CAD system to the lighting desk. ARRI, for example, has linked up with UK company White Light, which produces Autolight, a design system based on the popular Autocad drawing package. ARRI's desks also have a standard RS232 port for connecting a graphics tablet so designers can digitise rather than dictate lighting plans. The availability of standard computer and Midi (musical instrument digital interface) connections on lighting desks is opening the way for some of the new technologies emerging from the computer industry. ARRI's Ed is particularly interested in the potential of voice recognition, which he believes could be the ideal interface for lighting designers. There is also a lot of interest in the idea of distributed processing where the lanterns themselves have processors and memories. Vari Lite is the leader in this field. Its lanterns have the capacity to pan, tilt and change to any colour. So far their main use has been in the rock industry. But their potential for producing interesting effects in the theatre has been recognised by designers such as Hersey. He gave Vari Lite its theatre debut in Miss Saigon, and has used them in Children of Eden too. Children of Eden, which is based on the Book of Genesis, and Miss Saigon are at the leading edge in terms of computer technology. For example, Children of Eden relies on computer recorded samples for the animal sounds that accompany the cast on many of the numbers. These were put together on an Apple Macintosh by Martin Erskine, who is in charge of musical effects. For the performances, Erskine has downloaded the samples into a Roland MC50 sampler, which the conductor can activate by pressing one button. Also in the orchestra pit are numerous Midi instruments which are used to generate atmospheric sounds and more traditional notes. The sound mixing, which is the responsibility of Andrew Bruce of Autograph, also relies on computers for reducing the load on the analogue mixing desk. The one area of Children of Eden that hasn't been infiltrated by computers is the scenery. Automated movement of sets is still the preserve of shows such as Miss Saigon, which is noted for its helicopter and trucks. These are moved around the stage using a processor-controlled hydraulic system. And their entrance is made possible by 21 blinds which are moved by stepper motors controlled by an Atari PC system from Brain Boxes, specialists in industrial control. The use of computers to replace people, ropes and pulleys is only just beginning and it's not always noted for its reliability. While it provides a way of producing ambitious effects, it doesn't provide the economic miracle that would prompt every theatre manager to invest in the equipment. As Donmar's Albery points out, in today's economic climate theatre managers are looking for tangible returns. And these aren't going to be achieved by cutting a day off the lighting designer's rehearsal time, or replacing a part-time rope puller with thousands of pounds worth of computers.

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