This week we are looking at white balance, and the effect had by using the presets in our cameras settings both correctly and incorrectly in different lighting conditions.
White balance is a setting on your digital camera which allows for increased accuracy of the colours in a captured image. It allows for greater control and flexibility when needing to compensate for the myriad of different light sources and conditions that may be encountered, enabling a truer representation of the scene.
White balance presets on a typical DSLR camera:
- Tungsten lightbulb (household filament)
- Fluorescent lamps
Daylight (sun overhead)
- Cloudy (moderately overcast)
- Shade (shadowed)
- User defined
In general photography, having the white balance set to ‘auto’ will usually suffice. It is worth noting however, that the auto setting for your white balance is most effective when there is at least one white or colourless and bright element in the shot. Whilst not being essential for every situation, if your subject does not include something of this nature, the auto white balance can be prone to over or under–compensating the colour temperature of the shot.
It is in these circumstances that it is worth knowing about colour temperature, white balance, and how to measure it and adjust for the best results.
Here I am going to take a moment to give a big shout out to Grandpa (Malc) pictured in the following slideshow… Lesson 7 in Sydney there no sunshine to be seen, and so it was impossible to conduct the WB experiments in daylight. Back home in Adelaide for a couple of weeks, I’m here staying with Grandpa; who despite never quite being entirely at ease for too long in front of a camera, agreed to model for me to demonstrate the Kelvin colour temperature scale in sunlight. My Grandpa is my favourite person and my greatest support in life, and in my pursuit of graphic design. He turns 94 on Thursday, still plays tennis and is a deadset genuine Aussie legend.
The reason we need white balance settings at all is because different kinds of light have different colours. Our eyes are so effective at compensating and correcting for this that we often do not notice it until we looking at a photograph, when the colour cast suddenly becomes obvious. The majority of light sources, especially those that are natural light, give off a colour cast which ranges from a cool to warm, with neutral white in the middle.
The system of measurement for colour temperature from warm to cool is in units of Kelvin. The warmer a light source’s colour temperature is, the lower it’s number when measured in units of Kelvin. The red light of a flame will be at the lower end of the Kelvin scale, and the blue tinge of the sky on a clear day will be at the higher end.
White balance can be measured on two scales of colour: Warm to cool which is red or orange to blue, but also green to magenta. The warm to cool scale comes into play more commonly in situations like daylight, but modern artificial lighting situations such as Fluorescent bulbs may require adjusting on this green to magenta scale.
Experimenting in different light sources as in the examples here, and trying the different preset white balance settings is a great way to get a better understanding of the way these adjustment work and the effect of the Kelvin scale in photography.
More comprehensive info on the subject can be found here.