What is the principle behind pinhole cameras?

Pinhole cameras rely on the fact that light travels in straight lines – a principle called the rectilinear theory of light. ... If a camera has a lens, it is NOT a pinhole camera. read more

A pinhole camera is the simplest camera possible. It consists of a light-proof box, some sort of film and a pinhole. The pinhole is simply an extremely small hole like you would make with the tip of a pin in a piece of thick aluminum foil. A pinhole camera works on a simple principle. read more

A pinhole camera is a simple camera without a lens but with a tiny aperture, a pinhole – effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect. read more