The Color Of Light
Master white balance for greater quality and control
White balance is one of the new features we've had to learn to make the most of in digital photography. It's often seen as yet another technical hurdle photographers have to leap over in order to get a good image. Learn how to set it "right," and we'll have one less thing to think about while taking pictures.
But white balance is much more than just another setting on a camera. White balance, and most importantly, an awareness of the color of light, can become a creative option rather than a technical obstacle.
When we were shooting film, white balance wasn't an issue for most of us. If we were going to shoot outdoors, we simply used daylight film. If shooting indoors, we slipped a roll of tungsten-balanced film in our SLRs. Shooting under fluorescent light? We'd screw in an FLD filter to counter the greenish cast produced by those overhead tubes. Whether we completely understood the principle behind it or not, we knew that the wrong film under the wrong light would produce terrible color, and those images would be destined not for the living room wall, but for the wastebasket.
Now, with digital SLRs, we can set our cameras for whatever light source we're shooting under, on the fly. If we move from shooting outside on a sunny day to shooting in a small room lit only by 100-watt bulbs, we don't have to replace the film in our cameras. Instead, we quickly and easily set them to a different white-balance setting, assuring us that the camera would render neutral colors accurately. But what's behind all that?
Understanding The Color of Light
The color temperature of any light source is based on the experiments of British physicist, William Kelvin, who discovered that a piece of carbon produced varying colors at different temperatures. On the Kelvin scale ranging from 0 to 10,000, light at lower temperatures produces a warm, reddish glow (1,850-3,380 degrees Kelvin; candlelight, tungsten), while higher temperature ranges produce a bluish cast (7,000-10,000 degrees Kelvin; overcast, open shade).