Re:My Room in 3D
by bjelkeman-again on Sunday September 12, 2021 @09:30AM
(#28500964)
You see how the brain does white balancing quite clearly when working with LED lights optimised for salad, for example. The light has very little green in it and looks nearly pink. After a few minutes it looks less pink and nearly normal (depending on the lamps). Then go outside in daylight and everything suddenly look green, which takes a minute to go back to normal. The brain adds the green it perceives to be missing, and removes it again when it isn’t needed.
As I said, human vision has a kind of adaptive white balance that cancels out peaks like this to some extent. It also does that for artificial light sources with uneven spectra (neon light, blueish white LED lights...). [Side note: this is also the reason why cameras have adjustable white balance. A picture taken by a neutral sensor under some artificial lights is perfectly correct, but looks color tinted and wrong to the human eye afterwards, because the eye under the same conditions has a shifted white point.]
Why is this important? If you set up a light source in a renderer, you often get a pretty naive equal energy white as a default, which is simply not what you need for sunlight, even at noon under a clear sky.