Light at different times of day, in different weather conditions, under different artificial light sources has different colours. Unless the light has a strong tint, we don’t notice the colours of light with the naked eye as our brains make corrections to bring the colours back to their ‘normal’ colours. So, no matter what the time of day or what type of clear artificial light, we perceive white as white.
On the other hand, cameras are not sophisticated enough to make these corrections automatically without error (auto-white balance can be tricked) and photos end up with whites or other colours that are not quite as we visualised them.
Cambridge in Colour describes the colours of light and the different K (kelvin) measurements of the light:
Color Temperature Light Source
1000-2000 K – Candlelight
2500-3500 K – Tungsten Bulb (household variety)
3000-4000 K – Sunrise/Sunset (clear sky)
4000-5000 K – Fluorescent Lamps
5000-5500 K – Electronic Flash
5000-6500 K – Daylight with Clear Sky (sun overhead)
6500-8000 K – Moderately Overcast Sky
9000-10000 K -Shade or Heavily Overcast Sky
The colour spectrum moves from orange (for candle light) through neutral (around 5000K) to blue (in shade).
There are several conventional approaches to dealing with this to ensure photos do not end up with an unwanted colour-tint:
- Rely on the camera’s white balance (WB) settings to make the correction, for example select ‘cloudy’ or ‘tungsten’, which should do a reasonable job in lighting conditions that are not complex/multi-source.
- Use a neutral reference (eg grey card, or neutral grey in the scene) to set a custom white balance setting for you camera for a specific shoot. Usually done by simply selecting custom white balance, pointing at the neutral object and pressing the shutter.
- In post-processing of RAW files (in LR) – either by manually adjusting using sliders or using the dropper to select a neutral colour in the image (or even a separate image of a grey card shot at the same time).
However, I was impressed by Lovegrove’s approach using live-view on the Fuji X-T1. Rather than selecting one of the standard settings for unusual light conditions, he selects the K (kelvin setting), which allows scrolling through the full spectrum of light temperatures. He then uses live-view to inspect and adjust the image created by the camera until it meets his vision. I’ve used this and it’s fantastic being able to watch the colour of light change right before your eyes in live-view. So, effective WB adjustment on the hop without wasted time in LR later!
I would assume that this approach would also work on other cameras with live-view functionality.
Cambridge in Colour [online]. Tutorials: white balance. Available from: http://www.cambridgeincolour.com/tutorials/white-balance.htm [accessed 2.6.15]
The Lovegrove Blog [online]. Fuji X-T1 settings. Available from: http://www.prophotonut.com/2015/06/02/fuji-x-t1-settings/ [accessed 2.6.15]