In exercise 29 we are asked to take the same picture in three different intensities of daylight using three different white balance settings. The three types of light were full sun, shade at mid-day and evening and the three white balance settings were daylight, shade and auto.
The picture above shows the results in a comparative grid. The top half are the original photos and the bottom half are blocks of the colour of the “true” white card that is included in each photo.
I have learnt that the “auto” setting on my camera is reasonably accurate in full sun although the white card is a little more grey than it is in the day light setting; in shade it casts a stronger blue tint than the daylight setting as opposed to the warmer cast from the shade setting; in the evening sun the choice is similar, a warm cast from the shade setting or a blue cast from the daylight or auto settings.
I have always tended to leave white balance on auto and to make any necessary adjustments in photoshop so it is helpful to have worked through this exercise and to see that using the shade setting would give a warm tint to portraits taken in the shade or late afternoon.