 Filming had begun by August 1926 , when several scenes were shot in a cave that had been excavated for the production on <unk> Hill . Heuveldorp , unable to force the actors to play their roles seriously , shot several scenes with them acting as they wished before showing them the results ; upon realising that their acting had been disappointing , the cast began to listen to stage directions . Afterwards they began rehearsing each scene at least twice , with <unk> standing behind the cameraman and giving directions . 
