Colour Cast and White Balance

This exercise was to demonstrate the differing results from shooting using different white balance settings, especially if you are shooting in JPG only. If you are shooting RAW and using ‘auto’ white balance then the white balance can be completely adjusted in post production. However, if you can cut down on post production work by getting it right in the first place then so much the better. It is also a learning curve so in the future I will be able to troubleshoot if I see a certain colour cast caused by the wrong white balance. The shooting of the images was in essence relatively straightforward. I say relatively due to the lighting conditions set out in the final part of the exercise which I will cover when I get to it. The constraints of the exercise were this; shoot a scene under four different sets of lighting conditions (sunlight, cloudy, open shade, mixed lighting). Each scene was to be shot using four different white balance options (except for the last which is three); Sunlight, Cloudy, Open shade on a sunny day and Auto.

Firstly I needed to photograph a sunny scene, the results are below.

What I notice is that both ‘auto’ and ‘sunlight’ settings produce a very simlar colour and result. Possibly ‘sunny’ gives slightly more detail in the highlights and maybe a bit more contrast. There is nothing much in it. The ‘shade’ setting gives a very orange cast. The ‘cloudy’ setting gives a slightly orange hue but nothing like ‘shade’.

The shady scene shows some slightly surprising results. The image is of a concrete wall with no reflecting light. It is entirely ambient and grey in colour. For my eyes, the ‘auto’ setting gives by far the most faithful representation. All the other images have a heavy orange cast, especially ‘shade’, which is what the assumed setting would be for this scene. My thoughts are that although it was shot in the shade the scene still contained a high colour temperature causing ‘auto’ to come up with about the right setting. The fact that the ‘sunlight’ setting is the next closest looking would seem to back this up.

Cloudy scene. Again, the results are not entirely as expected. The ‘auto’ and ‘sunlight’ settings gives the most faithful reproduction whilst ‘cloudy’ exhibits some orange cast. ‘Shade’ gives a much more pronounced orange cast. Again, although entirely overcast the light temperature must have been quite high causing these results. The clouds were probably not terribly thick thus not giving very much cover.

The joker in the pack is mixed light. This scene entailed shooting at dusk whilst throwing in some tungsten lighting to confuse matters. Both these lighting conditions have completely different colour temperatures and as such the camera finds it very difficult to deal with (as does, on occasion, the photographer). Interestingly in this part of the world ‘incandescent’ lighting is a rarity and indeed I can’t remember the last time I saw an old fashion light bulb. In the main the ‘new’ CFL lamps are used which uses a discontinuous spectrum making post production tricky. So I used what I took for old street lightning outside my house (it gives a very warm orange glow) and shot in to the evening sky to see what the results would be. The use of the ‘tungsten’ setting gave a very blue cast to the image. This, I suspect, is due the still massive amount of available daylight. However, the streetlights appear white, which is pretty much what I would expect. Again, ‘auto’ deals with the lighting conditions very well and ‘sunlight’ also handles it very well (but still throwing a blue cast over the image). In these conditions I would invariably let the camera’s ‘auto’ setting do the work and then adjust in post production, but, it is very interesting to deliberately set the camera up for different lighting conditions to see the results.

What is born out of this exercise, I think, is what a good job the ‘auto’ setting does in general. Whilst, with experience, I can make a good educated guess at the lighting conditions it makes sense to get it in the ballpark and make adjustments later. However, the benefits of recognising the lighting conditions are different as this will enable to know when is a good time to shoot (if I have a choice). If I think the colour temperature of a scene is not what I want then it is probably worth coming back later or preparing better, rather than spending hours trying to get it right in the ‘darkroom’.

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One thought on “Colour Cast and White Balance

  1. Pingback: Judging Colour Temperature 1 | BA Blog

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