Born in Cuba in 1856 to an American father and English mother, Emerson studied medicine in England before taking up photography in 1885.
Emerson bought his first camera in 1881 and in 1885 founded the Camera Club of London. He was impressed by contemporary French painting, including that of the Impressionists, and argued for ‘naturalistic’ photography. For him, truth to nature consisted of accurately recreating the depth and density of space and atmosphere. Most of his pictures were taken in East Anglia in the 1880's, and his studies of landscapes, people at work, and scenes from daily life survive in the form of seven illustrated books.
His record of life in the Norfolk and Suffolk Broads was published in a series of books, the most important being the first, Life and Landscape on the Norfolk Broads (1887). Following its publication he made a study of photo-engraving processes which resulted in his subsequent books being illustrated with photogravures. Emerson renounced his views in 1890 with the publication of The Death of Naturalistic Photography. \
Emerson has been the subject of numerous solo exhibitions and his photography is held in the permanent collections of the Victoria & Albert Museum, London, the Museum of Modern Art, New York, and the Getty Museum, Los Angeles.