One thing you can do with mixed light sources is to gel some of them. This means you add a filter to the light to change its apparent color and balance it with your other light sources. If, for example, you're using tungsten floods to provide most of the illumination in a scene, but there are overhead fluorescent lights in the shot, you can put color correction gel over the fluorescents to make them match the incandescents, or you could gel your incandescents and make them look like the fluorescent lights. Then you set your white balance accordingly, and the camera sees everything the proper way: whites remain white and all color sources look white.

The exact steps for setting your white balance manually will vary from camcorder to camcorder, but it will always involve showing your camera a white or neutral grey card under the lighting that you'll be using (preferably a scene where your color temperatures match). If you watch the camera platform before a press conference, you may notice a cameraperson going up to the podium before the speaker arrives and holding up a grey card or a sheet of typing paper. This lets the cameraperson's colleagues zoom in on it and set their white balance properly.

While training the camera on the white card, set the exposure properly and fill the frame with white. Make sure to activate the manual white balance mode of your camera. Then you'll push the white balance set button and likely hold it for a second or two until you receive a message from the camera in the form of a word like good or possibly a flashing icon. Your white balance is set. Check your camera's documentation for the exact steps on setting white balance, and then try it in several different locations. Also try recording with an improperly-set white balance, so you can see examples of what happens if you're not careful.

Remember to reset your white balance every time you move from one lighting situation to another - especially when you are moving from outdoor to artificial light. Always do a manual white balance when you are working with mixed lighting (i.e., a scene with mixed color temperatures). If possible, gel the lights so that they're all the same color temperature. Companies like Porta Brace make white-balance cards on lanyards that you can connect to your camera's tripod. These cost about $5.

Don't forget to reset your white balance from manual when you leave a particular lighting setup. You don't want to discover the next afternoon that you've shot an hour's worth of video in sunlight with the white balance still set to fluorescent from the night before. I try to get in the habit of resetting my white balance to Auto when I shut my camera down. The Auto setting makes a guess that's rarely exactly right, but it's better than one that's completely wrong. The Auto function is often very confused by multiple light sources with very different temperatures.

While it's not necessary to remember the color temperature of tungsten bulbs as it compares to daylight, it's important to remember that the two are different and that they'll provide different lighting throughout the range of colors in your scene. Adjusting for these by using your white balance is critical to maintaining color continuity throughout your production.

Contributing Editor Kyle Cassidy is a visual artist who writes extensively about technology.