Studio lighting systems

My fascination with science, and physics in particular, made playing with light even more interesting.
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Like many adolescent nerds I found my way in high school onto the stage crew. Since, as my long-suffering wife knows, I have little skill with a hammer or paintbrush, I gravitated to the lighting crew and found it was great fun to manipulate the huge dimmer controls, which resembled levers the Wizard of Oz might use. My fascination with science, and physics in particular, made playing with light even more interesting.

Those ancient controls, now long since decommissioned I am sure, were little more than enormous resistors. Long-worn contacts made smooth transitions in dim corners of the sets a little more challenging than the minimal skill of a high school student could overcome, and instead of analog smoothness, I often created quantum energy steps. The selection of lights was simple: a couple of strip lights with the ordained red, blue and green gels, a few 500-watt fresnels, and even fewer ellipsoidals with patterns that were not very useful. But the effect was magical, turning a high school stage into a Scottish village called Brigadoon, the home of the elderly women of “Arsenic and Old Lace,” and a Harold Hill's parade ground. If I could revisit that stage as it looked then I am sure my jaded eyes would perceive a less-magical transformation, but suffice it to say those nights high above the stage in the lighting cage were an important part of hooking me on technology.

At that time, in the early 60s, a two-scene preset lighting board resembled something that the production designer of Frankenstein might have picked for the strange doctor's laboratory.

Today, compact fluorescents, HMIs, solid-state dimmers, computerized lighting boards, and dimmers on the grid are tools that lighting professionals of an earlier generation might have pined for.

Lighting technology is the original analog medium. Physics and engineering provide the tools — photons emitted from a source and controlled in direction and intensity. Ingenuity and creativity create the illusions. Lighting, when done well, does much more than provide the photons that are reflected from the set and focused on an imager to make television. It sets the mood, it replicates reality in places where lighting looks unnatural and it creates visual interest in much the same way a painter draws your eye to parts of his canvas.

However, light must be carefully controlled. The direction of the light, its intensity, the diffuse or point-source nature of the illuminant, and the color and color temperature of the luminous source are all-important in creating a visual illusion. Some are controlled in the instrument, some by the physics of the light source and some by filtering the output of the instrument. One, intensity, is controlled by the energizing source. A lighting system must, as a result, be looked at as a holistic system in which the lighting director uses all of the notes of his scale to play the proper luminous music.

When building a studio one tends to think first of the permanent, or semi-permanent, portions of that holistic system. A lighting control system varies only the intensity of the sources unless remote-controlled instruments with remote pan, tilt and focus are specified. I worked in a studio in Moscow where the lights not only had remote pan, tilt and focus, but moved around the grid under remote control from an elaborate control desk. That's pretty uncommon anywhere, but imagine it in a country where labor was easy to come by and not well paid. Lighting control systems today are generally computer memory systems that provide a stored value for intensity to each dimmer and vary those values according to a time line controlled by the operator. Most television lighting tends to be set once for the production and recalled for future use.

At one time dimmers were highly inefficient, creating both acoustic and electrical noise. They were therefore located outside the studio if possible. Planning for the electrical distribution to the grid had to take into account the loss of the interconnection and the effect of having multiple conductors interacting in ducts headed to the grid. Today, dimmers are much more efficient, and lower-power dimmers are not mounted on the grid itself, reducing the cost of installation and increasing the efficiency of the total system. Control wiring must be distributed instead of dimmer outputs. Time will tell if this strategy becomes expensive to maintain, but it is hard to imagine that it is not less expensive to install.

Instruments have also evolved considerably in the life of commercial broadcasting. New lamp technologies allow high-power instruments, like HMIs, which can also be much more efficient. The development of extended source luminaries, like compact fluorescents, has enabled energy-efficient operation for many types of sets. Such instruments are not applicable to all needs, as they tend not to be as easy to control as point-source instruments, but they have advanced quite a bit in the decade they have been available. Operations that run 24 hours a day, such as American shopping channels and 24-hour news, have benefited from both the energy efficiency and the long life of the sources. Where once dimming was not possible, it can now be fully controlled, and a variety of lamp color temperatures are available.

The range of options available to the lighting director presents an interesting challenge when designing a studio today. There is a temptation to make rash assumptions about the kind of instruments the studio will use, which has implications on the selection of control systems, dimmer size and count, and total power capacity that can be delivered to the grid. While some situations can be predicted well before construction and installation of the set (for instance, a 24-hour news channel or live newsroom set), general-use studios must still be planned for a reasonable “worst case.” Cutting off options early in the design phase of a project may allow the building budget to remain on track, but may seriously compromise future use that was not predictable or well understood. It is wise to employ a studio designer with a broad range of knowledge and project experience. One current client of ours anticipates a studio for major film work, commercials, episodic video production and live audience shows. Such use cannot come from a studio that has not been carefully thought through.

John Luff is vice president of business development for AZCAR.