Camera obscura used by Fox Talbot, c 1820.
© Science Museum / Science & Society Picture Library
A simple camera obscura which originally belonged to William Fox Talbot (1800-1877), the photography pioneer. Now incomplete, the device lacks the lens that would have focused a picture upon the glas screen in the top of the framework. In operation, an image was formed with a lens that was reflected off a mirror onto tracing paper from beneath. The artist was thus able to lightly outline the projected picture using a soft pencil. 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.