A Fine Balance
Ambarin Afsar demystifies the concept of White Balance, so that you can strike a perfect combination of colour and light.
This story was originally published in September 2011.
Pick your camera up. Look for the little button that says WB. Gaze at it for a while. You must find this to be such an absurd request. But, do go back to it and look at the White Balance icon carefully. Do you know that this little option can completely transform your photographs? Have you ever found yourself wondering how to use it? Or is it just another fancy, indecipherable icon on your camera?
Questions, questions and more questions. Asking the right questions is the first step towards finding the right answers. As you read on, you will come across all this information and more.
A Play of Light and Colour
Before we tackle White Balance, there is one tiny fact that you must know—light can be of various types. Whether we are talking about early morning light, the harsh light at high noon, a fluorescent bulb or a tungsten lamp on the streets, the way they look and the effect they create are quite different. Light and colour are intertwined, and the colour temperature of a light source can change the way the colours look in a scene.
To understand this, imagine that you are shooting a red door. Is it illuminated by sunlight? Or is it lit by a tubelight or a bulb? Colours lit by sunlight appear more vibrant and saturated, while the same colours look cold and less intense when lit by a tubelight.
What the Eye Sees
The human eye has the remarkable ability to adjust to varying lighting conditions, almost instantly. Since it can do this, colours look the same to you as you move indoors to outdoors, from shade to bright daylight or from one type of artificial light to another.
And What the Camera Sees
However, the camera is not so lucky. It cannot function in the same way that your eyes do. It has no way of knowing what a particular colour is supposed to look like. So, in order to help it accurately reproduce colour, it has to be told what sort of light is currently available.
In the days of film, this was done by using a film that is optimised for a particular kind of light, such as daylight film. Filters were also used to avoid colour casts. However, the digital world offers more convenience, as all we need to do is choose a particular WB setting.
The Idea Behind It
The idea is pretty simple. If the camera knows what the colour white looks like under a particular lighting condition, then it will know what every other colour is supposed to look like. So, changing the WB warms up or cools down the basic colour tones of the image to ensure that the whites turn out white instead of dull grey, light pink or blue.
The Preset Game
You must have noticed that the quality of light can range from the cool blue of early morning to the warm, orange glow of sunset. The reason why this happens is that light has different colour temperatures at different times. Based on this, certain WB presets exist in both compact cameras and DSLRs. The name of each preset corresponds to the light source it is supposed to be used under, to get accurate colours.
- Incandescent or Tungsten (2700K): Meant for cooling down warm, orange lights and tungsten lamps that are used indoors, this preset makes scenes without such lights look very, very blue.
- Fluorescent (4200K): This preset gets rid of the green casts caused by fluorescent lights such as CFLs by adding a magenta or purple cast. This cast becomes more pronounced in outdoor scenes such as sunsets.
- Flash (5400K), Daylight (5500K), Cloudy (6000K) and Shade (8000K): All these presets offer varying degrees of warm tones when used in tungsten lighting conditions or even in daylight.
- Auto White Balance: This is the joker of the pack. While the word Auto holds a lot of promise, it is not the universal balm people think it to be. Some cameras generally tend to produce warmer colours straight out of the box, while some cameras tend to overcorrect the colours.
Wrong Move? Or the Right One?
You do not necessarily need to apply the ‘right’ White Balance setting to every frame. What happens when you apply the ‘wrong’ setting deliberately? You will find that you can create all sorts of effects right inside your camera. The next time you go out to shoot in broad daylight, switch to Incandescent WB and underexpose the image by a stop or two. You will be amazed to see a daytime scene turn into a nighttime one!
Use the Cloudy or Shade preset to further warm up images taken in sunlight. You will end up with strong, golden hues. On the other hand, the Fluorescent preset can transform the orange colours of a sunset to soft, purple tones while the Shade setting can further enhance and dramatise the reds. Similarly, you can use the Incandescent setting to make snow, rain or even the sea look a surreal blue.
Balancing Black and White
Did you know that WB settings affect the grey tones present in a B&W image? Though WB has ordinarily been employed in colour photography, there are some implications for B&W images as well. To try this out, shoot a normal, daylight scene in the Monochrome or B&W mode and bracket for WB. You will find that the Daylight preset opens up the image, while the Incandescent and Fluorescent presets lend a darker tone.
If the light is not right, change it! For every photo you make with the correct WB, shoot one with the wrong setting. Use a WB bracketing feature if your camera has one, or simply change the preset manually. Once you understand that these settings, just like variables such as aperture and shutterspeed, are the means to creative expression, you will find yourself getting bolder with your experiments.