As you stare at this picture of lemons, realize that there is not a single pixel of yellow (570 nm) coming out of your monitor or mobile device right now:
Your computer screen can not produce any yellow light at all; it can only produce red, green, or blue light. If you were to get a magnifying glass and view this image of lemons close up, below is what it would actually look like:
Notice that you see only red and green pixels together, and that the blue pixel is turned off (black). Your brain interprets red and green close together as yellow. The disturbing thing about this is that if you look at a real lemon, you’re actually seeing real (subtractive color) yellow, because lemons absorb all colors except yellow which they reflect into your eye. But you’re seeing no real yellow in this picture as you can see from the closeup.
The reason your brain is fooled into thinking the lemons in the picture are yellow, is that your screen is showing some green and red dots close together, which your brain interprets as yellow. The reason your brain interprets this as yellow is that yellow falls between red and green in the color spectrum. Since our eyes have no direct sensors for yellow, we’ve developed the shortcut of assuming that when the red and green cone cells in our retina get stimulated together we’re probably seeing yellow. Our computer monitors take advantage of this by directly sending red and green into our eyes to stimulate those two colors of cone cells, which fools our eyes into thinking it’s seeing a yellow that isn’t really there.
No comments:
Post a Comment