© National Museum of Science & Media / Science & Society Picture Library
Albumen-silver photograph by Julia Margaret Cameron (1815-1879). Cameron's photographic portraits are considered among the finest in the early history of photography. She set up a private studio at her Isle of Wight home at the age of 48, after her daughter gave her a camera, and she became expert at using the collodion wet-plate process. She used friends, servants and neighbours as subjects, including the scientists John Herschel and Charles Darwin, and the poet Alfred Lord Tennyson.
'Cassiopeia', May 1866.