White balance is a feature many digital cameras and video cameras use to accurately balance color. It defines what the color white looks like in specific lighting conditions, which also affects the hue of all other colors. Therefore, when the white balance is off, digital photos and recordings may appear to have a certain hue cast over the image. For example, fluorescent lights may cause images to have a greenish hue, while pictures taken on a cloudy day may have a blue tint.
Since different types of lighting affect the way a camera's sensor captures color, most digital cameras and camcorders include an auto white balance (AWB) setting. The AWB setting automatically adjusts the white balance when capturing a photo or recording video. However, this setting may not always provide the most accurate color. Therefore, many cameras and camcorders also include preset white balance settings for different lighting conditions. Common options include fluorescent light, tungsten light (for typical indoor lighting), cloudy conditions, bright sunlight, and camera flash. By choosing the appropriate white balance preset, you may be able to capture pictures with more accurate color.
Some high-end cameras and camcorders also include a custom white balance option. This feature allows you to take a sample of a white object, such as a white wall or a piece of paper, within the current lighting conditions. By manually setting the white balance to the white color within the sample image, you can set the white balance with a high degree of accuracy. Of course, if you find out you have already taken several photos with the incorrect white balance setting, you can adjust the color afterwards with an image editing program.
Some digital video cameras also include a "black balance" setting, which is used to define how black should appear in the current lighting conditions. However, this setting is used far less commonly than white balance.