Three cameras associated with W H F Talbot, c 1820-1842.

UNITED KINGDOM - JULY 18: Three cameras used by the British pioneer of photography, William Henry Fox Talbot (1800-1877). On the left is a calotype camera with lens and metal focusing cover of 1841-1842; in the centre is a small experimental camera with lens of 1834-1836; and, on the right, the non-photographic camera obscura of c 1820 with a frame to hold the tissue paper for copying views by hand. Talbot used all three cameras in developing a photographic process which fixed a negative image on paper for the first time. (Photo by SSPL/Getty Images)