Agfa Isolette I with the Agfa Agnar lens (f/4.5 85mm), 1952-1958. With the shutter and aperture settings on the front of the lens this was an awkward camera to use. Initially I would set them using a light meter, but after a while I got used to guessing the settings, most of the time they were correct.
Of course you didn’t know you had messed up until the film got processed. Double exposures happened if you forgot to wind the film on.