In Judging Colour Temperature 1, we were asked to decide if the images needed correcting. All 3 images were taken using the Daylight white balance setting and the image of the book taken in the shade was definitely too blue. The low sun image was a little orange but was certainly more acceptable.
The 3 images below were all taken in direct sunlight at around midday.
In this first array of images above, taken under a daytime sun, the first image looks correct (it is the correct white balance setting for the shot taken) the third image (Auto) also looks pretty accurate, but the middle image - taken with the shade white balance setting - looks too orange. This is because the camera is correcting for the expected blue tint in the image (that the shade white balance setting is meant to correct) by reducing the blue and increasing the orange. It is completely wrong for this particular shot.
The 3 images below were all taken in the shade at around midday on a sunny day.
In the images above, all of which were taken in the shade, we can see that the first image - taken with the Daylight white balance setting - is too blue. This is because the camera is expecting a neutral light, when in fact it is a bluer light, generated by the reflected light from the clear blue sky overhead. As to be expected, the Shade white balance setting gets it about right, negating the blue effect. The Auto setting again does a decent job of correcting the blue tinge (although I possibly underexposed it a little)
The 3 images below were all taken in direct sunlight under a low (morning) sun.
In the final set of images were taken under a low sun, when the colour if light is more red. The Daylight white balance setting is expecting a slightly bluer light, so adjusts the image to make it slightly more orange. The Shade white balance setting does the same, only more so. Once again, the Auto setting is pretty accurate but leaves a little of the orange colouration.
These 3 sets of images show how the camera's white balance settings work to affect the colour balance in different outdoor lighting conditions. It is interesting to note that the blue tinge of an image shot in the shade or the orange tinge of an image shot under a low sun, is in fact accurate - the tinge should show in the image. For the camera to remove these altogether is not necessarily what the photographer might intend. A prime example of this might be a sunset, where the intention of the photographer is to record the deep reds and oranges produced by a setting sun. If the camera is set to auto white balance, the image will be automatically adjusted to remove the orange tinge and effectively spoil the shot. However, if a Shade white balance was chosen, the 'orangeness' would be exaggerated.