DPP Exercise 10 - Colour Cast and White Balance

The two images are of the shot taken in open shade (top image) and the shot taken in sunlight. Neither have been changed from the RAW image apart from applying 'auto' exposure. As required different white balance settings were used in each case to allow for comparison.

For the 'shade' shot ' Auto' provided an acceptable image but did not seem natural being slightly too blue. 'Daylight' produced a very cold looking image with a blue cast across the image. Cloudy had pleasant tones although there was a slight red cast to the image. 'Shade' produced the most acceptable image although slightly 'warmer' in appearance particularly the figures.

For the 'Sunlight' shot 'Auto' again was acceptable but probably too warm to be accurate. 'Daylight' gave

a result that was most accurate and pleasing to the eye. 'Cloudy' provided an image that was too warm with a red cast although visually pleasing. 'Shade' created a noticeable red cast.

The image was also taken in cloudy conditions in the same position as the 'Shade' image with virtually the same results with the 'Shade' setting producing the best overall result.

Taking the exercise a further step I introduced into the sunlit image a known white balance point ( using the X-rite Color Checker). Using this showed that a temperature of 5000k gave an accurate white balance without colour cast. The white balance of the camera gave readings of 7500k for 'Auto'; 5500k for 'Daylight'; 6500k for 'Cloud' and 7500k for 'Shade'.  Visually these differences were noticeable in the red colour cast particularly with'Auto' and 'Shade'.  I was surprised at the result of the 'Auto' setting although presumably this was to produce a more pleasing image when viewed.

I found this exercise very useful giving an insight into the differences between the various White Balance settings in the Camera. Getting the White Balance accurate is key to producing an accurate image but in some types of photography there will be a need to 'warm' the image because we tend to respond better to 'warm' images e.g. portraits.