What is white balance?
When the colours in a photograph appear natural, the white balance is correct. The colour of the light has a major influence on how colours are recorded by the camera. Different light sources have different colour temperatures.
Colour cast
When the white balance is correct, a white object appears white, red remains red, and so on. An incorrect white balance can cause one particular colour to dominate the image. This is known as a blue, green, yellow or red colour cast.
Removing a colour cast
The photograph below has a slight orange-red colour cast. You can correct this during post-processing by adjusting the white balance and, if necessary, the tint. White areas become more neutral and the other colours appear more natural. In the corresponding histograms, you can see how the colour distribution changes.
Colour temperature
The colour temperature of light is expressed in Kelvin (K). The concept is based on the colour emitted by a theoretical black body when heated to a particular temperature. At relatively low temperatures its radiation is reddish. As the temperature rises, the colour changes through orange and yellow to white and eventually becomes bluish.
Light sources and Kelvin
Different light sources have different colour temperatures. When setting white balance manually, many cameras allow you to select a Kelvin value directly. Experimenting with these settings can be very instructive.
Kelvin is an absolute temperature scale. Absolute zero is 0 Kelvin, which corresponds to −273.15 °C. In photography, Kelvin is used to indicate the colour temperature of a light source.
Warm or cool light
Interestingly, light that we perceive as warm has a relatively low colour temperature, while cool light has a higher Kelvin value. Candlelight, for example, is around 1,500–2,000 K, while typical daylight is approximately 5,000–6,500 K.
Setting the white balance
White balance can be set in the camera before taking a photograph and, when shooting RAW, can also be adjusted afterwards during post-processing. Many cameras have automatic white balance, which often corrects colour casts reasonably well.
Nevertheless, it can be useful to set the white balance deliberately before shooting, especially under constant lighting conditions. This provides consistent colour reproduction throughout a series of photographs.
Standard white balance presets
Cameras usually offer several white balance settings:
- Automatic
- Incandescent / artificial light
- Fluorescent
- Direct sunlight
- Flash
- Cloudy
- Shade
- Manual (Kelvin values)
Using a grey card
For accurate colour correction, you can use a neutral grey card. This is commonly used in portrait and product photography, where reliable and consistent colour reproduction is important.
18 percent grey
A traditional photographic grey card reflects approximately 18 percent of the incident light and is primarily used as a reference for exposure metering. For setting or correcting white balance, the important factor is that the card is spectrally neutral so that red, green and blue are reflected evenly.
How do you use a grey card?
Place the grey card near the subject and make sure it is illuminated by the same light. Then take a reference photograph. Depending on your camera, you can use this image to set a custom white balance.
When shooting RAW, you can also use the grey card during post-processing. Use the white balance eyedropper to click on the neutral grey card, allowing the software to correct the colour temperature and tint.
This method is particularly useful when taking several photographs under the same lighting conditions. If the light changes frequently, you will need to take a new reference photograph regularly.
Is everything in balance?
White balance and monitor calibration
It is not only the camera that affects colour reproduction. The monitor on which you edit your photographs also plays an important role. A properly calibrated monitor displays colours as accurately as possible.
If you edit photographs on a screen with inaccurate colour reproduction, you may unintentionally alter colours that were recorded correctly. A properly calibrated monitor is therefore important for reliable photo editing.
Experimenting with white balance
Photography is not only about technically accurate reproduction. Creativity also plays an important role. By deliberately experimenting with white balance, you can significantly change the atmosphere and appearance of a photograph.
A technically 'incorrect' white balance can therefore produce a very interesting creative result.
Below are several examples of experiments with white balance in Lightroom Classic.
The first example compares daylight and shade. Move the mouse pointer over the image. The version using the 'shade' setting becomes warmer and slightly more orange than the daylight version.
The second example compares daylight and artificial light. If you use an artificial-light white balance setting in daylight, the photograph develops a strong blue cast. Technically, this setting is not correct for the lighting conditions, but the effect can also be used deliberately for creative purposes.
Also read the page about colour space for more information about colour reproduction in photography.