Sir Joshua Reynolds' camera obscura, c 1760-80.
© Science Museum / Science & Society Picture Library
Sir Joshua Reynolds, the famous English portrait painter, used this early form of camera obscura. It is fitted with a mirror and lens that allows an image to be projected onto a piece of paper inside the darkened box that can then be traced out. This type of drawing aid is designed to fold flat into the form of a book when stored. Camera obscuras were known to the ancient Greeks, Chinese and were used by Arab astronomers in the 10th century to observe the Sun. During the Renaisance period, artists used camera obscuras to help them to draw more accurately.