Camera obscura from "L'Encyclopédie"|
The camera obscura (Lat dark chamber) was a novelty optical invention, and one of the ancestral threads leading to the invention of photography; photographic devices today are still known as "cameras".
Simply do it yourself by building a box and punching a hole in one of the walls - voilà! With a small enough aperture, light from only one part of a scene can strike any particular part of the back wall; the smaller the hole, the sharper the image on the back side. With this simple do-it-yourself apparatus, the image is always upside-down, although by using mirrors it is also possible to project a right-side-up image. Some camera obscuras have been built as tourist attractions, though few now survive. Examples can be found in Grahamstown in South Africa, Bristol in England, Dumfries and Edinburgh, Scotland, and San Francisco, California.
Camera obscura were used by artists in the 16th century, as an aid to sketches for paintings.
A small, hand-held version using photographic paper to record the image is known as the pinhole camera.