to preserve a photographic image
Niepce invented a way of recording the image on a metal
In 1839, another Frenchman, Louis Daguerre introduced a
better way of preserving the image. Many "Daguerreotype"
One problem with the Niepce and Daguerre processes was
"one-offs"; copies could not be made.
Englishman, William Fox Talbot, was the first, also in
1839, to capture a negative picture - in which blacks and
reversed - from which positive (right way round) copies