This George Butler was a good photog.
Aside from Albert Busek, George Butler took a lot of pictures of Arnold in his "natural atmosphere". No studio set-up, just what Arnold was doing at that very moment. George has gone on record saying that during the filming of Pumping Iron, Arnold's facial expression was natural, after Arnold started taking acting lessons he noticed a change in Arnold - he was more conscious of his expressions. These natural expressions were captured on Pumping Iron and in pictures, something perhaps we'll NEVER see again.