Early photography, A man working with a camera obscura. This projects an image of a scene onto a glass plate on which drawing paper is placed. The artist may then trace the scene as reference for later work. When light sensitive materials were used in place of the screen, the modern camera had been invented. Image taken from A Catechism of Photography Reprinted from the Photographic News. Originally published in Cassell, Petter and Galpin: London, 1859.