Quote: It's pretty difficult to use a large format camera with the lens "wide open". You are focusing on the screen and can go either side of the correct focus, even at infinity. You are highly dependent on stopping down to get any sort of depth of field and any decent level of focus.
That is why you hide under a cape, use a loupe to help you focus and the movements to control where the plane of sharp focus is positioned. All good fun, I think I can just about remember those days.......