My name is Guilherme and I’m a brazilian photographer and teacher. I’ve been having some difficulty finding some info in a research I’m doing, so please excuse me while I ask for help here. In a conversation with a fellow photographer it was suggested to me that Brassai’s, Sudek’s and Brandt’s bodies of work at night (1930 to 1933) happened immediately after a film was launched that managed reciprocity effect better. There is even a Time article that suggests such a thing. Would you know where can I find a source for these statments?