Bright opportunities
Dec 1, 1999 12:00 PM, Jerry Colmanero
As an A-V systems contractor, your customers may ask if you can do lighting, which may pose either a dilemma or an opportunity - to be or not to be a lighting contractor. Choosing to diversify your business as a systems contractor offers many paths of specialization, lighting systems being just one of them. Traditionally, lighting systems have been left up to the electrical contractor to implement with an electrical engineer as the designer or consultant, but a diverse field of venues, including sports stadiums, theatres, conference rooms, multipurpose facilities and churches, has widened the range of applications that are needed for lighting. This article is primarily concerned with systems contractors' considering entry into the lighting systems contracting market and some of the situations they may encounter at the onset. Most lighting systems fall into three distinct groups - theatrical, architectural and presentation.
Theatrical systems are specifically for performance spaces where plays, musicals, symphonies and other events take place on a designated stage, and the audience is primarily an observer. Usually, a theatrical lighting systems contractor is in the business of supplying not only the lighting equipment, but also rigging, curtains, set construction, risers and any theatre supplies. A systems contractor looking at theatrical lighting systems would have to consider a wide range of specialties in order to compete competently with companies versed in the particulars of the theatre. It is my recommendation that unless a separate dedicated division devoted to the theatre market is considered for your business, these applications should be left to the specialists.
The electrical contractor of a building project generally installs architectural systems. General interior and exterior lighting is covered. Simple control is used and is not integrated with the theatrical system. The architect or the electrical engineer designs the system to fit the general illumination needs of the building. Board meeting rooms may have a bit more sophisticated control to dim lights during a video presentation, and this may or may not bein conjunction with the A-V control.
The combination of both theatrical and architectural lighting into one system is not a new concept, but because of the market demands for new levels of control sophistication, a new category needs to be defined. For the purposes of this article, I will call this new segment "presentation lighting". Systems contractors stand at the threshold of this new presentation lighting segment, and in this segment are the keys to how a simple school play or church service is transformed into a participatory event.
Churches, above all, have had the greatest impact on the A-V installation industry. A church may have a 40-piece choir, a full orchestra, song leaders, a video presentation and a drama presentation all in one service. This has increased the demand for the highest quality in audio in such a tough environment as those with high reverb times, many open mics, pastors who go out into the congregation and guest artists taking the audio system to the cutting edge to bring about the best presentation. Likewise, the church is not the best environment for video, but the demand for quality is high. The congregation must see the image at wide angles in a high ambient light building, and at the same time, the system must not distract the congregation from the service itself but just be an informational source. Presentation lighting demands are no less.
Typically, a church does not want to be a theatre. Theatrical style presentations may happen from time to time on the church altar area even though there may be no altar, yet the congregation is usually an active participant. There is no proscenium, no wings, no backstage and no built up sets as we would expect in a theatre. Rigging and counter-weight systems are not used and usually not planned for in church construction. Some churches, however, produce dramas every bit as compelling and complex as any Broadway show, but the church must still remain a church. Guest speakers, informational seminars and various youth educational activities take place in the church, yet a church is not a classroom or a board meeting room.
What divides the church environment from the theatrical and the architectural designs of lighting is that the presenter (pastor, choir, musical group and drama team) and the audience as a congregation interact with each other. This does not happen in any other situation at this level. Lighting control is used in this situation not to divide the presenter and the congregation, but to enhance the sense of unity churches demand. There is no curtain of light and dark that comes between the participants the way it would in a darkened theatre or in a meeting room where the audience must focus to the front.
"Do you do lighting?" I am sure that at one time or another you, as a contractor, have heard this question asked. You must arm yourself with some self-reflection before answering yes to a potential customer and realize that with any area of specialization, education and trained personnel are the keys to success. Theatrical systems with the full complement of rigging are best left to companies that are committed to that field. Typical architectural systems fall under the realm of the electrical contractor. Presentation lighting leads the system contractor to integrate his customer's needs to have full presentation capabilities with the A-V systems he is installing and/or designing.
There is a basic short list of requirements for presentation lighting control that a contractor should consider when choosing a line of products. Levels of quality and performance for audio systems, for example, have evolved to meet the market demands, and lighting control systems are no different in this respect. For example, the product must be UL listed; there are no compromises here for the sake of safety and your own business liability.
DMX
Further, few protocols have become the reigning standard in their chosen field as DMX512. From the chaos of almost zero compatible devices in 1986, the year of the standard's initial publication, there are today few lighting control devices manufactured that are not compatible with DMX512. The present version is the USITT DMX-512 1990. DMX512 was originally envisioned as an additional control protocol to be used alongside existing protocols. Rather than coexist, it has displaced almost all proprietary protocols. The standard is maintained and published by a trade organization called the USITT (United States Institute for Theatre Technology).
DMX becomes the common language to the dimming system from the lighting control console and/or A-V control panel. Most architectural systems do not use DMX as their primary control protocol, but in order to have a successful integration of theatrical and presentation lighting, DMX ultimately must be present at the dimming section of the lighting. Many architectural dimming manufacturers either offer a separate interface option for DMX or already have a port for the connection of DMX.
DMX uses an XLR five-pin connector, although some manufacturers have sometimes used the three-pin connector. Belden 9842 is a common cable used for install applications. DMX is a bit fussy about the cables through which it is propagated, and even though I have seen Belden 8451 used with some success, DMX is still data, and what works and what is correct are two different things. Refer to Table 1 for pin connections. You will notice that pins 4 and 5 are designated as spares. Various companies have used these to transmit data about dimmer and control status, contact closure for remotes, and other control protocols. A few years ago, the USITT issued a warning about some companies' sending voltage down the spares, which reportedly resulted in equipment damage when mixed and matched with different manufacturers using the spare pins for different applications.
The theoretical length limit of a DMX512 cable (from source to final termination) is around 3,000 feet (914 m). To work reliably at this distance, you must have perfect source, termination and cable of adequate cross-section. The data rate for DMX512 signals is 250,000 bps. This is fast enough to put a DMX512 signal into the category of signals knows as RF (radio frequency) Because of this, I have seen some enterprising installs where parallel T-splits were used, creating an RF antenna, and to use a purely technical term, the results messed with the DMX transmission. With this arrangement, there is an unterminated length of cable hanging off the split, and this can cause all sorts of problems. Although the circuits all check out fine with a meter, when DMX data is actually flowing through the wire, all sorts of odd things happen. The DMX signal must be properly terminated. A simple resistor of 120 V to 150 V connected between pins 2 and 3 of the five-pin connector of the last device in the line solves this problem.
Additional DMX termination points throughout a facility allow the user to add additional dimming or automated lighting for special events. At these points of termination it is advisable that a switch designed to introduce the termination resistor into the circuit be installed so that when equipment is added for temporary applications termination is a simple operation, and the integrity of the signal is maintained.
Architectural interface
Most architectural lighting systems offer the ability to set up various scenes or looks for the general lighting of a facility. A simple wall panel with access to these scenes placed at the entryway of the building is common. Various manufacturers have developed their own control protocols, digital and analog, for this application. Development of these protocols has happened outside of the realm of DMX because DMX is a standard developed primarily for the theatre market, and it has been only recently that a demand has emerged for integration of architectural and theatrical style control. When looking at a dimming system, whether it was designed originally for the theatre or the architectural markets, make sure that the manufacturer offers an interface. These two types of control systems must address a common dimming system, regardless of the type of control protocols used.
The most common scenes for regular church services, weddings and funerals are accessed simply from the architectural control panels. More sophisticated events and their scenes are controlled from a dedicated lighting control desk. The ability to dim the house lights for special presentations from both control systems enables the greatest amount of flexibility with the least number of operators and setup time.
Scene memory
The architectural control system and the theatre control console must have the ability to operate independently of each other. This may seem like a contradiction to integration, but some systems rely on the theatre control console to have extra pages of memory for house lights and architectural control. In dedicated theatre systems, this is common, but for presentation lighting, it is not acceptable. In applications of presentation lighting technology, a lighting system operator is not always needed, and a certain level of automation is often required. Architectural control systems are not necessarily designed for theatre use and do not have crossfade and multi-scene control.
An architectural lighting system offering less than 24 dedicated architectural scenes in memory could not cover the various types of events taking place in the church or multipurpose facility. Scene memory for the architectural system should reside exclusively in the architectural dimming system yet may still be overridden by the theater style lighting console via a DMX port. The scene control residing in the theater console should remain independent of the architectural system.
Subpatch
Softpatching is the method by which DMX is routed from specific theatre lighting console channels to the dimmers. A single DMX line can address up to 512 channels of dimming control. There can be more than 512 actual dimmers if particular dimmer channels share the address routing. The theatre console can have few, say 32, control faders, but those fader channels are routed to any number of the 512 dimming control channels. An independent Softpatch for the architectural control system is a must. Because the dimming system is shared by both the architectural and theatre control, the dimming system must make the distinction between the commands. In a theatre environment, the audience area goes dark, and all the lighting control is dedicated to the stage area; any architectural control can be simple and independent, but presentation lighting presents a set of different demands.
Here is a common applications example. In a wedding, the focus is decidedly on the couple being married. Upon the bride's entry into the church the aisle lights are brought up 100%, the congregation area is dimmed to 70%, and the altar area slowly fades up to between 50% and 100% as the bride nears. During the vows, the couple wants to be brightly lit and the congregation area of the church dimmed to 50%. As the couple marches together to exit the church, all lights are brought up to 100%. This would obviously involve control over the theatre-style lighting at the front of the church and the church's architectural lighting, which only an integrated system can provide.
Softpatch capability allows the control commands to be routed to the proper dimmers for the above applications example; a different softpatch may be used for regular Sunday services. Softpatching should not be confused with scene memory; softpatching gives you the ability to use certain dimmers that may be used for architectural functions. Through this control the architectural lighting becomes a part of the dynamics of the presentation.
Bring it all together
People are the most important aspect in the design and installation of presentation lighting. Churches want to be dynamic in their presentations and depend upon the lighting system to perform as a part of the overall A-V package. The pastor, music minister and youth minister should all be involved in the initial design stages of a lighting system; all of their application ideas should beaddressed and the lighting system designed to meet them. These individuals use the building in different ways but must share the facility and the equipment used in it. If one of them is left out of the decision-making process, their department suffers.
The electrical engineer should be aware of the load requirements of the dimming system. All too often, this step is ignored, and inadequate electrical supply stops comprehensive lighting designs from ever coming to fruition. A minimum of 400 amp three-phase independent service just for the lighting system is typical. Any less would severely handicap expansion possibilities. Dimming systems generate heat, and the HVAC engineer should be aware of the cooling requirement for the lighting dimming system.
A distinction needs to be made as to what the role of the electrical contractor will be in the installation of the project. The electrician should be responsible for all power feeds coming to and leaving the dimming system, installation of the architectural lighting fixtures, and conduit runs to control locations. The contractor supplying the presentation lighting system is responsible for the interconnect of all data and control lines, console and control placement, dimmer setup and softpatching, console programming and training the client in the proper use of the system. The HVAC and electrical contractor should be made aware of the design demands of the lighting system immediately after the design decision is made. All too often, the presentation lighting is considered a separate trade from the electrical contractor, and as such, the electrical contractor is never given the opportunity to properly budget for the project. Have all contractors closely involved to avoid these pitfalls.
Design for expansion
Availability for extra amperage designed into the electrical panel is a must; if the system requires a 400 amp three-phase panel, have a 600 amp three-phase panel installed. Additional lighting, dimming and the addition of automated lighting fixtures are purchase decisions the client will usually make within the first year after the initial installation of the lighting system. Spare data runs to all locations, and data runs to locations not presently in use are a must. Make sure that the control systems (both architectural and theatre) are expandable beyond the 512 channel limit. Although 512 channels may seem like a lot, with automated lighting fixtures becoming more common, they are used up quickly. Some automated fixtures take up to 36 channels of DMX to operate and a client's minimum purchase could be as many as four to six of these automated fixtures.
Expanding your business into presentation lighting will ultimately require the hiring of specialized staff as your business grows. Employing a person with broadcast and theatre lighting design (or at least a proven track record in one of those areas) would be the best step forward in building yourself a share of the market in the installation and design of presentation lighting.
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