How to read a photograph

One of the first well-known photographers, Roger Fenton was commissioned to report on the Crimean war by a Manchester print dealer. The Ordnance Wharf, Balaclava, 1855 shows cannonballs being unloaded and stacked. Photograph: Roger Fenton

Julia Margaret Cameron's portraits were based on Biblical scenes and the works of Milton and Alfred Lord Tennyson. The Angel at the Tomb/ Freshwater, 1869 Photograph: Julia Margaret Cameron

Peter Henry Emerson attempted to make photography as expressive as painting. His 1895 image Marsh Weeds was influenced by naturalist painting. Photograph: PR

Eugene Atget saw photography as a documentary process. He concentrated on the old-fashioned trades of Paris, such as this Seller of Café au Lait, Rue Mouffetard, c1898-9. Photograph: Eugene Atget

The amateur photographer Louis Vert 'discovered empathy... asking us to put ourselves in the subject's position', writes Ian Jeffrey. Petit Patissier au Jardin du Luxembourg, Paris, c.1900 Photograph: Louis Vert

Henri Cartier-Bresson was the pre-eminent modernist photographer. This photograph was taken in a brothel in Alicante, Spain, 1933. Photograph: Henri Cartier-Bresson / Magnum

Cartier-Bresson 'liked open-air eating because it gave great scope for character study', writes Jeffrey. First paid holidays, France, 1936. Photograph: Henri Cartier-Bresson / Magnum

In 1935 the documentary photography Dorothea Lange was hired to work for the governmental Resettlement Administration (later the FSA), producing photographs of rural poverty in Depression-era America. Woman of the High Plains, Texas Panhandle, 1938. Photograph: Doretha Lange

Jack Delano, born Jacog Ovcharov in Ukraine, emigrated to America in 1923. Like Lange, he was employed by the FSA, but was asked to produce 'more positive' images of America. Connecticut Tobacco farmer and Wife, Connecticut, September 1940. Photograph: Jack Delano