If computer screens render different colours by filtering white background light through red, green and blue pixels, and black is the absence of colour, how do computer screens reproduce the colour black?

Question

The most intuitive answer would seem that black pixels get “switched off”, but I know that’s not true because I can tell when a monitor is switched on and off even if the screen is just black. There’s a sort of “black glow” to them.

In: Engineering

Answer 1

I think part of what you are experiencing is called “color constancy”. Your brain is telling you that the black parts of the image are actually blacker than they are, because they are part of an image that your brain needs to make sense of in changing light conditions. There’s a related thing called “lightness constancy”. Your monitor can’t physically make things blacker than what you see when the monitor is turned off.