- Post Production
| How the Camera Works | White Balance | Light and Exposure|
| Using a Gray Card | Manual Exposure Control | Manual Focus Control |
How to White Balance the Camera
White balance has to do with differences in color caused by the intensity or "temperature" of light. The color of a light is entirely dependent on its source. It is almost never pure white, but rather takes on different shades, such as a yellow or red tinge at sunrise and sunset, or a blue tinge in a shaded area or in-doors under a tungsten light.
Our eyes automatically adjust to the difference in color temperature and so we see white, no matter how yellow or blue the light is or how tinted the subject is as a result. Where as our eyes make this adjustment automatically, the camera has to compensate for this tinting by using filters, generally speaking one for sunlight and one for tungsten. These filters are built into video cameras. When the camera is in automatic mode, it will decide which filter to use for you, and usually it does a pretty good job. But if the image looks wrong on the LCD, if everything is tinted blue or if everything seems yellowier than it should, then the white balance is off. Your primary source of light may be the sun, but the camera thinks its a light bulb, or vice versa. This can easily happen if you move indoors after shooting outside or outdoors after shooting inside. For this reason, it's good to know how to set the white balance on your camera. If it looks wrong when you're shooting, the image will not magically correct itself when you play back the tape.
You should be able to set the white balance through the on-camera menu. In the more manual-friendly models, there may be a white balance button somewhere along the body of the unit. (Check the manual, for instructions.) Use the "indoor" setting when the source of light is entirely artificial. The outdoor setting should be used when shooting outdoors in the sun. If it still looks wrong, try putting the camera on automatic. If the color looks wrong even in automatic mode, your camera may be having trouble balancing light from more than one source. For example, when shooting in a room with lots of windows and lots of overhead lights, the color of the light can change from one part of the room to the next; the light is yellow near the windows and blue near the opposing wall. This happens because the camera is reacting to the overall color of the light entering the lens, rather than the color of the light near the subject of your shot. The result is that the highlighted portions of the frame are tinted either blue or yellow.
If it still looks wrong in automatic mode or if you don't trust the automatic settings to make precise adjustments, you should set the white balance manually. To do this, put the white balance control in your camera on the manual setting. Once the white balance icon is flashing in your viewfinder or LCD, hold up a white piece of paper or card next to or in front of the subject of your shot, and then zoom the camera in on the white paper so that it completely fills the frame. Push the white balance button on your camera and hold it until the white balance icon stops blinking. Then zoom out again and check the colors in your viewfinder or LCD against what you see with your naked eye. By doing this, the camera is forced to look at a true white color at that point of your subject, and then balance the rest of the color spectrum around the true white that it sees.
For a cool special effect, manually white balance on a specific color instead of a white card or white piece of paper. This essentially tricks your camera into treating whatever color you've white balanced on--red, blue, green or whatever--as if it were white. The result is that all the colors will be skewed to one side of the spectrum. A good example of this can be seen in the 2001 Steven Soderbergh movie Traffic. Scenes shot in Mexico are all hot and yellow. The Los Angeles scenes are cold and blue. It's a cheap trick (cheap in the sense that it doesn't cost a thing) yet can be an effective way of enhancing the story.
If you're using an older camera, VHS, Super-8, etc., you may not have the option of setting the white balance. That's not to say the problem doesn't exist for these cameras, it's just that the camera insists on compensating without your input. In this case, you should try to avoid mixed lighting situations. Shoot entirely in the shade or entirely in the sun and don't shoot near windows while the house lights are on. Fluorescent lights can be a problem. They tend to cast a greenish light and video cameras generally don't have the proper filters to correct this. If at all possible, they should be avoided, whatever camera you're using.
If the light is extremely low in the scene, then setting your white balance may be difficult or impossible. Ideally, what you should do in this situation is break out your light kit and set up some lights. But before you can do that properly, you really should know a little something about lighting and exposure.