Nokia's revealing the secrets behind ClearBlack: its display technology that, even under the brightest sunlight, renders black as black as blackest night during a dark spell. Wedged above the E7
, Lumia 800
displays are three thin layers, a linear polarizer, a quarter-wave retardation film and a reflecting surface. When light enters the first layer, it vertically aligns the "wave vibration" of the light so when it hits the retardation layer, it begins to rotate towards the right. Hitting the reflecting surface causes it to reverse, becoming left-circularly polarized before passing through the retardation later again, where it polarizes horizontally. This enables the polarizing filter up top to screen out horizontally polarized light, meaning it doesn't reflect back in your face. Why (we hear you ask) then doesn't it happen with the light from the display itself? Because it only passes through the second half of the process, it doesn't become horizontally aligned, leading to that beautifully dark display reaching your peepers. It's a clever and elegant solution that we can't help but be impressed at, even if we've used up the world's supply of the word 'polarize' in order to explain to you.