One Approach to Energy-Efficient Lighting
By John Gates
All of us are constantly under-the-gun to do more with less in our jobs. And there are plenty of sales people that will sell you almost anything with that single goal; get more and pay less. There are some snake oil salesmen out there that would have us all believe that we must forget everything we have learned about lighting and use only their "new" lights; supposedly in the name of energy efficiency and economy. As if only their lights are economical and efficient. This is simply not so. The real trick is to operate efficiently and economically, yet still produce good pictures: the ultimate goal in television.
There are any number of relatively new lights, using a wide range of light sources, that allow Lighting Directors to create attractive images in an energy efficient manner. For lack of a better name, I call using the combination of these sources; Hybrid Lighting. (An LD might call it, "Having your cake and eating it, too!")
Hybrid Lighting utilizes the latest quartz key lights, color correct fluorescent fill lights and low voltage back lights. In other words, using the appropriate type of light source for each task.
If a "key" light provides the basic exposure value, creating attractive highlights and shadows that reveal form, enhance certain features and conceal less attractive features, than a controlled "hard" light (like a fresnel) allows you to separate one key from another, using the best placement, angle and intensity for each person or object being lighted. State-of-the-art quartz fresnels do this very well and very efficiently (and relatively economically).
If a "fill" light provides a smooth light to control the contrast range within a picture, by "filling in" (not eliminating) the shadow areas created by the key light, than a "soft" light (like a fluorescent light) does this very well. There may be no other light as soft a fluorescent lamp, simply because the entire lamp envelope radiates diffused light. And, fluorescent lamps are incredibly efficient (with a long life) compared to studio type quartz lamps. Great advances have been made in creating color correct fluorescent lamps for television and film production. And there are several fixtures that utilize grids, screens or louvers to control the inevitable spill from these softlights, making them LD friendly.
If a "back" light provides a controllable source to separate one person or object from another, and to provide additional "detail" (like hair and fabric) within the picture, than a controllable "hard" light allows you to back light one person or object separately from another. Dedolight makes a small, low voltage light with the smoothness and control we associate with a fresnel, but with much longer lamp life, using much less power.
This hybrid approach provides Lighting Directors with energy efficient lights that allow them to design lighting in a "traditional" manner, with tools that are familiar to them and with no limit to the wide range of lighting "looks" they can create.
Another benefit of this Hybrid Lighting is that the differences in equipment are transparent to the viewer: They do not perceive any difference from the use of these various "new" light sources, simply because the LD is able to light people and sets using the right light for the task at hand.
I can think of only three alternatives to the hybrid approach:
- Light things as you always have, using 30 to 50 year old technology, and pay the price in power cost and lamp replacement cost.
- Light things using the snake oil, one type fits all, wall-o-mush lights; making your talent look like "Charlie Brown" cartoons.
- Don't use any lights and make radio.
The short and long term savings of the Hybrid Lighting approach are dramatic: reduced power consumption every minute of operation for both lighting and HVAC. Use less power and generate less heat; then you have less heat to remove from the studio. These HVAC power savings are combined with low replacement cost, long-life, light bulbs. Just one example: The low voltage back lights use a 100 Watt, 2000 hour life lamp with about an $8.00 cost to replace 650W to 1kW fresnels using 200 to 400 hour lamps, with a $ 24.00 plus replacement cost. While the initial light fixture cost is from 25% to 100% more than the alternative traditional lights, the ongoing operating savings quickly make up this initial difference.
You can witness these systems in use in the Boston area on WABU-TV 68 for the nightly "Adler On-Line" and weekly "Consider This" programs.
John Gates is an award winning lighting director for television and film production with a long history of SMPTE activities. John is a Fellow of the SMPTE and currently is serving his third term as a Governor for the Eastern Region. Contact him at Gates Service Group, email@example.com.