White Balance

White balance (WB) is the process of removing unrealistic colour casts, so that objects which appear white in person are rendered white in your photo. Proper camera white balance has to take into account the "colour temperature" of a light source, which refers to the relative warmth or coolness of white light. Our eyes are very good at judging what is white under different light sources; however digital cameras often have great difficulty with auto white balance (AWB). An incorrect WB can create blue, orange or green colour casts. Understanding digital WB can help to avoid colour casts created by the camera's AWB and help to improve photos under a wider range of lighting conditions. Most cameras provide a number of predefined choices with names such as cloudy, daylight, flash and incandescent for adjusting white balance.


To further complicate things, some scenes will have a number of different light sources, such as indoor and natural lighting. Under such circumstances the AWB will be an average of the colour temperatures and will tend to exaggerate the difference in colour temperature for each light source. Setting the camera to incandescent will produce one photo, whilst setting it to daylight will produce another. However neither would be correct, the solution to this scenario would be to custom the white balance for the actual light conditions. Most cameras also come with a Custom White Balance setting. In this mode take a photo of a white object (a sheet of white paper or a professional white balance card also known as a grey card) under the lighting conditions of the scene. Set your camera to Custom (a mode in the white balance menu) and fill your viewfinder with the white paper. When you press the shutter, your camera will take a reference picture and use it as the source for the rest of your photos white balance (read the instructions for your specific camera model). Remember when you change locations and or lighting you will need to take a new white balance reference.

AWB

Tungsten

Sun

Custom WB