Inside your camera is a heroic but largely overlooked slice of silicon. The chip in question takes the data supplied by the camera’s sensor and turns it into a recognisable image. This marvel of electronics is referred to as the image processor.
One of the tasks of the image processor is to interpret the white balance settings of your camera and apply them to your images. Here’s the interesting thing though. You too have an in-built image processor that interprets the visual data coming from your eyes. This image processor is of course your brain.
The brain is remarkably adept at performing an auto-white balance, making us believe that light is reasonably neutral when it is often anything but. It’s only when the colour bias of light is extreme (such as the golden glow of candlelight) that we really take note.
I deliberately used a warmer WB than was technically ‘correct’ to
emphasise the romantic mood of this image of a rose.
The human brain responds emotionally to colour (as far as I know the image processors in cameras aren’t emotional, though it would be nice to think that they enjoy a good artfully composed photo too).
Certain colours are very evocative, reflected in sayings and phrases that are commonly recognised. Think ‘I’m feeling blue today’ or ‘I’m in the pink’. We can use this propensity to associate colour with emotion to add impact to an image.
By using a white balance (WB) pre-set on your camera you can compensate for the colour bias of light so that any white in an image is perfectly white.
So, for example, when you use the tungsten WB pre-set the camera adds blue to the image to compensate for the orange bias of tungsten lighting (just in case you were wondering an ordinary incandescent light bulb is a tungsten light source). However, although this may create a technically correct WB it doesn’t mean that it will feel emotionally or aesthetically right.
You can control an image’s WB more precisely by setting a precise Kelvin value on your camera. A Kelvin value specifies the colour temperature of a light source. The lower a Kelvin value the warmer and more red the light source, the higher the value the cooler the light source.
A tungsten light has a colour temperature of approximately 2800˚K whereas the cooler light of an overcast day has (slightly counter-intuitively) a higher Kelvin value of approximately 6000˚K. By setting a Kelvin value of 2800˚K on your camera your images become bluer.
Again this is because you’d normally use a specific Kelvin value to compensate for the colour bias of a light source by adding the opposite colour to the image (by adding blue to compensate for a red bias and vice versa).
A cooler, blue tint to this shot helps to convey a sense of menace and foreboding.
This is when altering a camera’s WB setting becomes a creative act. By deliberately using the ‘wrong’ Kelvin value (or an ‘incorrect’ WB pre-set) we can change how a photo is perceived emotionally. By using a lower Kelvin value (making the image cooler) an image will look bluer.
Blue is associated with emotional distance, sadness and detachment. It is also calming and tranquil. Use a higher Kelvin value and the image will look warmer and redder. Red is associated with excitement, emotional engagement and joy. More negatively it also represents danger.
If you’ve a willing subject try shooting a portrait this week using both the correct WB, a cooler setting and a warmer setting. You’ll be amazed at the difference between the three images. As an added twist try shooting a sequence of images with your subject happy and then a sequence with them looking sad or emotionless.
When your subject is (metaphorically) blue does a warm WB look odd? Is there more impact when the subject’s apparent mood chimes with the colour balance of the image? Answers on a postcard please. In the meantime I’m off to sit in front of a golden fire and not think too much about the cool blues of the wintry sky outside.
If you would like to learn more about How to be Creative with White Balance then why not consider taking Phil Malpas’s course on Capturing Colour: Going from Ordinary to Extraordinary