I recently purchased an old shutter that mounts on the front of LF lenses with a maximum barrel diameter of 49 mm The shutter has no markings to indicate manufacturer or country of origin. It has three positions - O, M and Z. O is open for focusing, M is a single speed of 1/50 to 1/100 sec (instant) and Z holds open while depressed for time exposures (as B). My Exakta model I in addition to B has Z for the setting that would be T in the U.S. Can one of the multilingual European photographers tell me what the German words are for O, M and Z ? I am curious. :?