The major improvements in the FM2 compared to the FM were silicon photodiode light meter sensors, limited automatic dedicated electronic flash control and a mechanically-timed vertical metal shutter (bearing mounted for reduced friction and extended life) reaching a top speed of an unprecedented 1/4000th second, with an X-sync of 1/250. Both the 1/4000th second and 1/250th second were possible even with no battery. This shutter was able to reach such ultra-fast speeds because its titanium honeycomb curtains had a travel time of 3.3 milliseconds, half of typical vertical travel metal-bladed focal plane shutters of the time.