For this exercise I needed to create images that had what I considered a pronounced colour cast and correct it. A colour cast describes colours in the image that looks unnatural to the eye and has been affected by the way or conditions in which the photograph was taken. I found that with modern DSLRs this is actually trickier than it sounds. The automatic white balance on these cameras tends to cope very well with lighting conditions making it hard to ‘accidentally’ get a very bad colour cast. What will normally cause problems are mixed lighting situations such as natural light combined with artificial lighting. Even so it will still attempt a best-fit solution and normally comes pretty close. This, in my eyes, doesn’t leave a significant colour cast. I went out to deliberately shoot for a colour for the first image I used and in the second case found myself in an appropriate situation which I could use.
In the first instance I took a photograph of a street scene heading towards the photographic golden hour. This meant that the streetlights had just been switched on but that also there was still an abundance of natural and quite bright light involved too. I set the white balance to cool white fluorescent to give the image a very cool blue colour cast.
There is very little to choose between the images as far as the colour and detail goes. There is slightly more detail in the sky from the RAW version as I might expect.
However, as I start adjusting the white balance using the road’s tarmac as the neutral grey, some very clear differences start occurring. The sky in the JPEG conversion is very difficult to control If I want to have white face of the houses opposite. It ends up with a uniform orange cast due to the lack of detail retained by the JPEG. The sky in the RAW version is easier to control and in fact the slightly warmer orange cast as a whole is more representative of the actual sunset colours I saw although if reflection I don’t think it looks particularly natural either. This may be due to looking at the previous colder version above to compare. Indeed, I have found when adjusting white balance in other images that it can become problematic to entirely rely on the eye for the adjustment as the brain cannot help but compare to the previous version. In these cases I use the neutral grey ‘dropper’ tool and adjust from there or simply walk away after the adjustment and come back later. I don’t think either of these images are a particularly good representation of what I could see with my eyes. However, they both cope admirably well considering I shot them specifically to have such a bad colour contrast.
For the second set of images I was inside a very strangely lit area of a temple. Above me was a red and white-striped canopy attached to yellow tarpaulin around the sides, which was filtering the sunlight. The sunlight was also coming in naturally at the sides of the canopy between the two parts of tarpaulin (as can be seen in the images below). To compound this, fluorescent lighting was being used inside the temple itself and hanging from the canopy. I shot this image on automatic white balance (AWB). This gave the original image a very distinct yellow colour cast, especially on the faces of the actors. When I look at the series of shots that I took in this location (as I shot many more than this), the brain starts to tell me that this colour cast is normal and I can almost ignore it. As an image on its own, it clearly needs correcting.
Once the change of white balance is applied (I used the skin tone to balance the image) there is a drastic and pleasing change in colour cast. The faces take on a much more realistic hue. The differences between the two are rather difficult to pick out once they have both been reduced in size and converted to JPEG for the internet. In the originals on my photographic software there is clearly less available colour and contrast to work with in the JPEG version. The bit of natural light is also more difficult to work with, as it was a clear highlight the needed treating. The saturation of the colours has been altered to a more natural state (the originals to me looked over saturated). The JPEG in this image copes better with the colour alteration than the first image. I suspect this is due to the already large amount of colour in the frame drawing the eye away from the detail but also that the AWB has coped very well with the situation in the first place and although there was a significant colour contrast, the range of contrast was not too pronounced and therefore easier to deal with in post processing.
This does leave me realising what a good job of balancing the colour AWB does but also that, as the person with autonomy over the situation (i.e. the photographer), I should always be aware of the colour in a given scene, whether it be at the point of taking the photo or during the post processing.