Illuminations: Color Temperature Strategies

Jim Stinson
July 2005

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When you're lighting a shoot you're responsible for color temperature. Sure, videographers set the camcorder white balance, but they can only work with the light you give them; and in real-world production, that light is rarely the nice, clean 3200K temperature that makes the camera smile. You usually face a mixture of incandescent and fluorescent light, or either (or both) fighting window light. And that window light is anywhere from 5000K all the way up to nine and change. This would be no big deal if all the light sort of blended into a compromise color temperature, because the camcorder can be set for a wide range of nominal "whites".

But light doesn't do that, so there you are preparing to tape the CEO in her executive office, with a halogen spot for a key light, a huge window for fill, and a fluoro ceiling for rim and background lighting. Great: one side of the CEO is orange, the other side's blue, her hair is edged in green, and her priceless rosewood walls look like limed oak. What's a poor gaffer to do?

Plan ahead, for starters, beginning way back before your first lighting job.

Before you even assemble your lighting kit, decide whether to go with halogen or fluorescent lights. That decision will determine whether your native lighting temperature is 3200K or 5000K (+/-). (Indoor color fluorescents are also available, but for simplicity we'll focus on the more common outdoor types.)

In making your decision, consider two big factors: the pros and cons of each lighting approach and the kinds of available light you're most likely to find at the locations you frequent.

Halogen lights are lightweight, compact, and powerful. They're available in spotlight and broad flood designs that allow precise control of beam size, shape, intensity, and fall-off. Without doubt, they are the most flexible, versatile lights you can use. On the down side, halogens are hot and they're power pigs. The popular 1,000 watt size sucks nine amps, so just two of them will blow a 15 amp household circuit.

Fluorescents are exactly the opposite: they sip power sparingly, and because of this electrical efficiency, they pump a lot of light per watt and they never get dangerously hot. But fluorescents work only for soft lighting, usually as pan lights. (As yet there is no such thing as a fluorescent spotlight, although screw-base fluorescents are now available, as the sidebar explains.) Because most units contain multiple tubes, fluoros are big, heavy, and clumsy, even though ingenious vendors like Lowel have done wonders in minimizing their bulk.

So, if you need small size, portability, and lighting finesse, consider halogens. If low heat and power are important, look at fluorescents.

But wait, there's more. If you work in a school, an office, or any public building, nearly every location you shoot in will be lit by a fluorescent ceiling grid and most likely windows as well. Fluorescent video lights will be a close match to the light already available at the scene -- a very good reason to choose them for your basic light kit.

On the other hand, if you're working high-quality professional productions, you may routinely disable all ambient illumination and light exclusively with video lights. Since you won't have to match cool ceiling or window light, you won't care if your versatile, powerful halogen instruments emit a much warmer light. So: step one is to standardize on a halogen or fluorescent light kit.

Step two is to lay tools in to cope with the ambient light at locations, so that all light sources are the same color temperature. You have three options here, and you may choose to use more than one at a time.

The first choice is to convert your video lights to the prevailing color temperature. To match daylight, direct 3200K halogen light through a series 80 blue filter. To sync with ambient incandescent light, cover 5000K fluoro pans with a series 85 orange filter.

Your second option is the exact opposite: to convert the ambient light to match your halogen video lights. Windows can be gelled with large sheets of that same 85 orange filter (more on that later). Ceiling fluorescents can be sheathed in orange tube. In some cases, it's easier to place sheet filtration over existing fluorescent fixtures.

Finally, you can swap out the existing lamps (if not the daylight). Movie-grade tubes are available -- if a bit pricey -- and now you can obtain medium (household) screw-base "curly" fluorescents that will replace most light bulbs in practicals (lamps and such that are visible in the frame). See the sidebar for more details.

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