An interesting and very useful setting which digital cameras offer is the so-called White Balance (usually marked as WB in the camera menu). As we know, the intensity of the sources of light is different in the different segments of the light spectrum. The incandescent lightbulb emits mainly in the red and infrared part of the spectrum, which is also the spectrum composition at sunset and sunrise, while at noon we have predominantly ultraviolet radiation. Films used in analogue cameras usually have sensitivity designed for daylight and they correctly reproduce colours under such light conditions. If you shoot with film under incandescent light, the resulting photos will have a strong yellow and red cast. There are special films designed for incandescent light and if we want to have correct colour rendition under such conditions, we should buy this type of film.
Below you can see an example of how different a picture taken under mixed light conditions can look. We have two light sources – artificial light from the candles in the foreground and natural daylight in the background. In the photo on the left the white balance was manually set to match the upper segment of the bride’s dress. It is truly white, but still illuminated by the warm light of the candles. This is why the daylight seeping from behind has a distinctive blue cast. On the right the white balance was set to match the daylight, but this led to a warm yellow and red hue in the foreground. It is hard to say which is right and which is wrong in this case. I would say it is a matter of personal preference. When your camera has an option for manual white balance setting, you need to place a white sheet of paper in front of the lens and by pressing the right button indicate to the software that you would like all other colours to be set accordingly based on the white colour of the sheet. Another option is placing a special white cap for white balance on the lens. If you shoot in RAW format, you can later adjust the colour temperature to your liking.
White balance is the right colour setting in the camera itself. But what exactly is ‘right’? Do we mean right based on our human perceptions or right based on some technical characteristics? The example below was shot in RAW format. The picture on the left has deliberately incorrect white balance enhancing the beautiful warm feel of the sunset.
In the next two examples from a portrait session, I experimented with white balance in the shooting process. The sunset illuminated the model’s face. I shot with a white balance of 7000K and 4000K. At higher color temperatures the warmth of the sun is felt, but at lower temperatures there is a strong color contrast of warm / cold colors, as described in the chapter “Color and color harmony”
This interesting function can sometimes be used to create unusual colour combinations and effects. For example, by setting the white balance to ‘electric light’ and shooting during the day, you will have photos with a bluish hue, recreating the feel of early morning.
Maybe you are asking yourself why we still see real colours at any time during the day and under any type of incandescent light. This is due to the fact that our brain processes the information it receives from the eyes and its white balance is much more perfect than any digital camera software.
When we shoot technical photography, fashion catalogues, furniture or products, we only take into consideration the technical parameters of the scene. A furniture maker or clothes manufacturer is not interested in what type of light we use for their products. He only cares that the colours should be as close as possible to the actual ones, because he does not want to face claims from dissatisfied clients misled by the pictures in the catalogue.
Any good photograph is a successful synthesis of technique and art.