Camera Obscura

light · optics · art history · cool physics

Dark box magic. A camera obscura is a dark chamber or box with just one small hole in it. When light from outside passes through that tiny hole, it projects an image of the outside world onto the opposite wall, but the picture is upside down and backwards.

Light travels straight. This happens because light always travels in straight lines. When light rays from different parts of a scene pass through the tiny hole, they cross over and flip the image, creating that upside-down effect.

Artists loved it. Hundreds of years ago, artists used camera obscuras as a tool to help them draw and paint accurately. They could trace the projected image to get the right proportions and details.

Photography's ancestor. The camera obscura is like the great-great-great-grandfather of modern cameras. The word 'camera' actually comes from the Latin word for this dark chamber.

Nature does it too. You can see camera obscura effects happen naturally during a solar eclipse, when sunlight filtering through tree leaves creates little circular images of the eclipsed sun on the ground.