I think Michael was speaking about Weston's photographs, not about his own pictures. He once wrote to me that EW used apertures up to f64 and that there was only once, he thought, that EW made a smaller aperture. The system used by Weston on some of his lenses may have been US stops, which is a different system from the current system. In this system, 256 must be equal to 64 in our system. This confirms other discussions with some friends good connoisseurs of vintage photography.
Originally Posted by David A. Goldfarb