What is camera white balance?
White balance (WB) is the process of removing unrealistic color 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 "color 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 unsightly blue, orange, or even green color casts, which are unrealistic and particularly damaging to portraits. Performing WB in traditional film photography requires attaching a different cast-removing filter for each lighting condition, whereas with digital this is no longer required.
Understanding digital white balance can help you avoid color casts created by your camera's AWB, thereby improving your photos under a wider range of lighting conditions.
The following table is a rule-of-thumb guide to the correlated colour temperature of some common light sources:
Color Temperature Light Source:
1000-2000 K Candlelight
2500-3500 K Tungsten Bulb (household variety)
3000-4000 K Sunrise/Sunset (clear sky)
4000-5000 K Fluorescent Lamps
5000-5500 K Electronic Flash
5000-6500 K Daylight with Clear Sky (sun overhead)
6500-8000 K Moderately Overcast Sky
9000-10000 K Shade or Heavily Overcast Sky
Setting white balance on your camera.
Most digital cameras these days allow us to set white balance from presets within the camera.
As you can guess, this is where the camera determines what the best white balance setting is. It doesn't always get it right but it'sworthwhile using.
You may not see much of a difference with this and auto white balance but is meant to be used in daylight
The shed setting. Images shot in shade can be quite blue so this will add some warmth to it.
The cloud setting. Adds some warm tones to normal daylight pictures. Be careful with this as sometimes your pictures can look quite yellow.
The light bulb setting. Counteracts the strong colour cast from tungsten lighting (usual light bulbs).
The strip light setting. Compensates the greeny-blue of fluorescent lights.
The lightning bolt setting. Using flash can introduce a bit of blueness and this setting adds some warmth.
Custom White Balance
Most of the new digital camera also have "Custom" White Balance setting which allows you to set your own white balance to reflect the current lighting situation.
Using a Grey card to set Custom White Balance.
A Grey Card represents a neutral colour usually 18% grey and is perfect for setting the white balance.
To use the Grey Card as the basis for an in-camera custom white balance, make sure enough of the center of the frame is covered by the card in your picture to be properly read for white balance. Fill the frame with the card. Next, go through the menu to select that picture for your custom white balance. Finally, set the camera to the custom white balance setting.
If you are shooting RAW, then simply place the grey card in the same light source as your subject and take a test shot. In your post editing software, simply grab the white balance picker tool, place it on the grey card in the test image and your white balance will automatically be set.
What type of Grey Card should I buy?
The grey card should be 18% grey and the most accurate one I have tried is the one manufactured by Lastolite and is availabe in our eBay Store.