Camera Obscura
A darkened room or box in which a small aperture projects an inverted image of the outside world onto an inner surface.
In depth
Described as early as the fourth century BCE and used as a drawing aid by Renaissance artists, the camera obscura supplied the optics of photography centuries before anyone could fix the image chemically. Every camera since is a camera obscura with a recording surface added at the back.
Examples in practice
A darkened room with a small hole in the shutter projects a full-colour, inverted view of the street across the opposite wall.