Thanks for the link and what a coincidence as there was just a TV show on him on the Knowledge channel last night. He was a professional photographer in that he worked at the university taking medical and science photos required for classes. His street shots were his hobby and for most of his life he did this just for himself. It was only in the later part of his life that this massive hobby, I think he said he had over 100,000 photos, that he became known for his artistic insights into street photography