I know what WB is and I know how to adjust it to obtain the desired results. But still there is a question I ask to myself from time to time: what's the reason for needing different white balances depending on the colours present in the scene to get a natural result, if those colours also changed in-place when our eyes where looking at the scenes?
For example, if I develop a landscape with a 'Daylight' WB preset, the result looks good. If now I go indoor, switch a light on and shoot again, why do I need to do a proper tungsten WB to obtain natural colours? why the Daylight preset produces an orange unreallistic appearence on my image? the camera doesn't lie, it just captures light on a tri-band RGB basis. Why the channel alignment (WB) that was fine for the outdoor landscape produces a natural result to my eyes, but need to change to a tungsten channel alignment (WB) to get the same feeling my eyes had being there?
The only answer to me is the way our brain works, performing by itself some kind of WB or temperature compensation. In the tungsten scene the light was really very orange, like the camera captured it, but our visual system involuntarily corrects it to make it appear more 'natural'. If we develop the indoor scene with Daylight white balance and look at it, our visual system will not correct it since our environment prevents us from doing it.
What do you think?
BR