The title pretty much sums it up. Why is it that reflected light from a television is blue, even if the picture itself isn’t blue?
You sure you mean “reflected” light? Or are you talking about the light emitted by the television itself?
Whoops, I did phrase it a little funny. What I mean is light FROM a television or monitor, reflected BY another object, like a wall.
He’s talking about that blue glow that you see emitted from the windows when a crt is used in a dark room. I’ve always wondered the same thing. Even an apparently white image leads to blue light reflecting off of walls and nearby surfaces.
Here’s my hypothesis: The light is diffusing in the atmosphere at unequal rates of dispersal, and anyone who’s seen the daytime sky knows that blue light disperses best.
If that’s not plausible, I’ve got nothing.
It’s a bit more complicated than that. Our perception of color and “netural” such as a white or gray that is not biased toward blue or red is very flexible. What we think of as white light ranges from a very reddish under tungsten bulbs to very blue when standing in open shade under the sky. Our perception of color adjusts so rapidly that we rarely notice it unless we know to look for it. Anyone who has done much color photography knows they must be aware of it and to correct it. Films are formulated specifically for daylight or tungsten and digital cameras have electronic balancing of neutral white.
TVs typically put out a white that is unusally blue which looks natural to most people despite the fact that ambient room light may be much redder from tungsten light. I’m not sure of the mechanics but our eyes percieve the radiant source from the TV and reflected light from other objects to match. Cameras are not fooled. I’ve done some experiments where I set white balance on the TV and the rest of the room looks amber to red. Setting it with a white card in the room makes the TV look very blue.
The same reason the sky is blue?