video techniques

White balance has to do with differences in color caused by the intensity or "temperature" of light and how a video  camera compensates for these differences in color.

Sunlight is rarely pure white, but rather takes on different shades, such as a yellow or orange tinge at sunrise and sunset, or a blue tinge in a shaded area. Sunlight also has a different color temperature than artificial light.

Digital video cameras usually come with an automatic white balance meter that essentially tells the camera which intensity of the color white is in the picture, and the rest of the colors in the spectrum are adjusted accordingly to make the video look as natural as possible.

But there are cases where a video camera may misconstrue the intensity of the lighting because it is measuring the general intensity of the light it sees at the spot where the camera is located rather than the intensity of the light at the location of the subject of your shot.

The result is either a blue or orange tint to the video you shoot.

For example, if your camera is in bright light, but the subject of your shot is in the shade, the camera will be reading the light as more yellow in tone because the camera is in yellowish sunlight. The subject of your shot thus will come out looking slightly blue, because the subject is actually lit by bluish shade light.

Or your camera may be in a room where the intensity of the light is from an artificial source like fluorescent lamps, but your subject is next to a window and in sunlight. In this situation you also will have a white balance problem.

To fix this, you need to hold up a piece of white paper next to the subject of your shot, and then zoom the camera in on that white paper. Then push or select the white balance button on your camera to set the proper white balance at the position of your subject.

The camera essentially is forced to look at a true white color at the location of the piece of paper, and then balance the rest of the color spectrum around that true white that it sees.

Video cameras also usually come with white balance pre-sets, such as artificial light or natural sunlight.