Some interesting craft knowledge onveyed in this YouTube video. He uses a Leica M6, which has an onboard exposure meter that is much too fiddly for rapid use. So he takes a reading off his hand (using a Weston meter) and then leaves the camera set on this. (Good trick: I’ve used it from time to time.) What he doesn’t deal with in this clip is how to focus manually at a pace that’s quick enough for what he’s trying to do. My hunch is that he uses a 35mm or 28mm lens set to f8 — which gives enough depth of field that anything reasonably central in the frame will be in focus.