eli5 How does projectors projects black in a bright room?

Question

I am in psychology class, the light’s are on and I clearly see this black squares on white background. How is this possible? https://www.instructables.com/Optical-Illusion-Black-Squares-and-Gray-Dots/

In: 1

Answer 1

Projectors don’t actually project black color, they just don’t project anything where the black parts are. It’s just our perception, because relative to the white/bright parts, those areas seem darker.