Dr. Joseph Maria Eder & Eduard Valenta
Both Josef Maria Eder and Eduard Valenta studied the natural sciences at the University of Vienna and began working together in 1880. They were teachers and wrote for scholarly journals, conducting research in the fields of photochemistry and the scientific uses of photography. Eder co-founded the Graphische Lehr- und Versuchsanstalt in Vienna in 1888 and was its head until 1923. Valenta taught there too, from 1892 on, and succeeded Eder as head in 1923. Eder published the four-volume Ausführliches Handbuch der Photographie in 1884, of which a third revised edition was published in 1932. He edited the Jahrbuch für Photographie from 1887 to 1931.