Educated at home because of ill health, he was first attracted to photography by an exhibit of James Craig Annan's work.
The child of a wealthy family, Warburg pursued many interests: music, linguistics and entomology. He took up photography about 1880 and was soon writing numerous articles for German and English publications. Joining RPS in 1895, he was elected to its council in 1913 and to fellowship in 1916, also serving on several committees. Warburg lectured and wrote extensively on the process and showed Autochromes at the annual RPS exhibition for twenty years.
Warburg worked in the pictorial style, chiefly using platinum and gum-bichromate processes. He also produced many autochrome transparencies (1907). Although his earlier work was realistic (1880s), he worked in an Impressionist style for the remainder of his career.
He was a member of the advisory committee for the Hamburg International Jubilee Exhibition of 1903. He joined the Postal Camera Club in 1899 and was a founder-member of the Pictorial Group in 1921.