Of course not. The swatch on the left isn’t black. It’s a mid-range gray, and so is the one on the right. The swatch in the middle isn’t white. It’s darker than the other two.
What if I told you that the swatch on the left is black acrylic paint, the sample on the right is a jet-black dress shirt, and the swatch in the middle is a white newspaper?
The x-factor is sunlight and shadow—and the pesky tricks that our visual systems play on us.
The samples were all lifted straight out of a single photo taken in my sunny front yard yesterday morning. I was sitting in front of a refrigerator carton painted black.
Even when the tones are adjacent (between 2 and 3), our minds tell us that the “white” is lighter. It's good to keep this in mind when we're painting.
The visual cortex uses context cues to override the luminance information from the retinas. Professor Edward Adelson of MIT developed the “checkershadow illusion” to show that the white square (B) in shadow is equal to the black square (A) in light (click to enlarge).
Here’s a rule to remember: In bright sunlight, a newspaper in shadow is darker than a black shirt in the light.
For more about the checkershadow illusion, check out Dr. Adelson's website and this interactive demo.
More on GJ about that painted backdrop, link.
Thanks to Professor Adelson.