the shortest shutter time for MF shutters is mainly limited mechanically by the firmness of the materials used. Only very few horizontal 35 mm shutters with rubberized cloth blinds could reach 1/2000 sec. (OM-4, Leicaflex...), most only 1/1000 sec. The acceleration and the forces which act on the materials are even much higher with the longer way of the MF shutter. More modern shutters like the Copal Leitz shutter use the shorter 24 mm way and steel blades, the most modern types which run 1/4000 or 1/8000 sec., use aluminum, titanium foil or high strength high-tec polymers. A central shutter like the Compur comes to its limits with 1/500 sec., 1/1000 sec. with a central shutter is rare.