Automatic White Balance
Automatic white balance means that the camera analyzes the picture and decides on its own about the color adjustment.
The simplest method is that the camera assumes that the brightest part of the image is white and uses this as a basis to calculate the corrections.
But nowadays when even cheap cameras can recognize faces in an image immediately a lot more complicated and refined methods are possible. The camera manufactures do not publish detailed descriptions for their algorithms.
Every camera uses such an automatic white balance as a default unless you set something else. The automatic white balance is usually visualized with a display of „A“, „AUTO“, on the left is an example of a Nikon D7000’s LCD display (click to enlarge).
My experience with automatic white balance on several cameras is:
- Sunlight is usually no problem and allows the automatic white balance to produce good results.
- When shooting outside in the shade or under an overcast sky you will probably get colors with too much blue, like the example at the beginning of this article.
- Under electrical (tungsten) light colors used to get too much red but nowadays there are cameras that do pretty well, returning only slightly warmer colors.
- No automatic white balance works perfectly in all situations.
(Note: This is the only sentence in the enumeration without a ‚probably‘, ‚usually‘ etc. ;-).