- Bill Zarchy — Writer / Photographer / Storyteller - http://billzarchy.com/blog -

NAB 2011: Greening the Film Business—LED Fresnel Lights

Fan-cooled models of the Arri L7-C and L7-T shown hanging in the Arri booth at last month’s NAB Show.

(Article first published as Greening the Film Business [1] on Technorati.)

It’s a vicious cycle in the film business. We use scads of energy to light our sets, usually trying to make them look as natural as possible, then we use scads of energy to cool them. If we can reduce the power required for lighting, we can save money two ways.

In the olden days of production, when I was starting out in the business, most movie lights (except for big arc lights) had tungsten or quartz lamps. These lamps employed a simple technology, like Edison’s light bulb, pushing so much electric current though a thin wire filament that it glowed and gave off light … and heat. Tungsten is still the most mature, least expensive, hottest, and least efficient lighting technology available.

Advances in green technology have brought energy-efficient fluorescent and HMI lights into film and video production for a couple of decades now. And over the past few years, professional lighting units using light-emitting diodes (LEDs) have become an important part of the production world, using as little as 10% the power of conventional lights. But these new LED units are primarily broad light sources, difficult to control, and in many cases they throw multiple shadows when not diffused.

Last month at the NAB Show, I was heartened to see several manufacturers investing time and money into fresnel lights with LED lamps. Lights with fresnel lenses, originally invented for use in lighthouses, feature distinctive concentric-circle patterns in the glass. They have long been a mainstay of professional film lighting, because of their controllability and flexibility (their beam angle can be adjusted from a concentrated “spot” to a wider “flood” setting), and for their consistent intensity across the width of the beam of light.

I found it difficult to assess the performance of the LED fresnel lights at the Show, given their positions among many light sources in the various booths. The Arri lights seemed to throw an even pattern, from what I could tell on a wall 20 feet away. The Lite Panels booth had too many sources mixing together to assess any one of them critically, but I did manage to cast some hand shadows with the DeSisti lights, and I was not impressed by the multiple shadows I saw. And it was impossible to evaluate color at all.

Arri L7-T LED fresnel light with rear heat sink on exhibit at the NAB Show
Arri L7-D daylight color LED fresnel light
Arri L7-T tungsten color LED fresnel light
Arri L7-T tungsten color LED fresnel light showing dimmer control
Arri L7-C controllable color LED fresnel light with rear heat sink
Color control panel on Arri L7-C controllable color LED fresnel light
Color control panel on Arri L7-C controllable color LED fresnel light

Arri [2] showed prototypes for their L7 series LED lights [3] with 7″ fresnels. Some models will be available with cooling fans, and some with large heat sinks for silent applications. The L7s are internally dimmable or DMX-controllable, use an Arri-developed LED array, and beam angle can be continuously focused from 15 to 50 degrees. Arri says their L-Series fixtures reduce electricity usage by 75% and their LED light engines last 200 times longer than conventional tungsten fresnels. They should be available for purchase in September.

Lite Panels Sola6 LED fresnel light
Lite Panels Sola6 LED fresnel light control panel
Lite Panels Sola6 LED fresnel light
Lite Panels Sola ENG LED fresnel light
No heat: Lite Panels Sola ENG LED fresnel light

Lite Panels [4] showed prototypes of their daylight color Sola series LED fresnel lights [5]. The Solas each use a single LED, are internally dimmable from 100% to 0 with no noticeable color shift, and they are DMX controllable. Beam angle can be varied from 10-70 degrees. Instant restrike, flicker free light output, no ballast necessary.

DeSisti LEDonardo 120w LED fresnel light
DeSisti LEDonardo LED fresnel lights

DeSisti [8] showed final prototypes of their new LEDonardo LED fresnel lights [9]. The LEDonardos should be available for sale in about three months in both tungsten and daylight color models, and feature one LED light in each. All models are DMX controllable.

Mole Richardson [10] did not exhibit LED fresnels, but a Mole rep told me the company is currently involved in researching ways to add this green technology to their product lineup. It’s not easy, he told me, to avoid multiple shadows and green-colored light output. Mole should be showing an LED fresnel prototype at NAB next year.

We fight war after war over oil as the US and most of the world grapple with the inevitable decline of fossil fuels, and the increase of greenhouse gases and climate change. We must continue to find ways to save energy in every way possible. LED fresnels are another vital step in trying to green the film industry.