18th Century camera obscura. Historical artwork of a man standing in front of a camera obscura. A camera obscura is an optical device that led to photography and the camera. It consists of a box or room (as here) with a hole in one side. Light from an external scene (left) passes through the hole and strikes a surface inside (right), where it is reproduced, rotated 180 degrees (thus upside-down), but with colour and perspective preserved. When light sensitive materials were used in place of the screen, the modern camera had been invented. From Weltall und Menscheit (Universe and Humanity), by Hans Kraemer (ca. 1880).