White balance is used to adjust colors to match the color of the light source so that white objects appear white. Subjects may be lit by a number of different light sources, including sunlight, incandescent bulbs, and fluorescent lighting. Although to the naked eye all these different light sources may appear colorless, in fact they emit light of different colors. The image sensor in a digital camera will reproduce these color differences just as they are, with the result that without additional processing the color of the photograph would appear to change according to the light source. Auto white balance automatically processes the image to remove unwanted color casts by, for example, making photographs taken under incandescent bulbs more blue to correct the reddish cast of this type of lighting. Normally, auto white balance will produce the desired results without the photographer having to worry about the type of lighting. If auto white balance does not produce the desired results, the photographer can choose from a number of fixed white balance options according to the weather or the light source. The photographer can also choose a setting for direct sunlight or incandescent lighting to introduce a deliberate red or blue cast according to their creative intent.
Sample Camera Displays
White balance is displayed as shown below.