Catalysotype

The catalysotype is a photographic fine printing process developed by Thomas Woods in 1844 from the early days of photography.

Thomas Woods (1815-1905) was an Irish doctor, photographer, and inventor. The catalotype he developed required only 1–2 seconds of exposure time instead of the then common calotype and was easier to use. Instead of the usual silver halides , he used ferric iodide (iron iodide, FeI ₂ , Ferrum iodatum) as a light-sensitive substance.