Shutter Failure
After about half a million exposures the shutter in my DSLR called it quits. A part of the linkage that holds the blades of one of the shutter curtains together as they move had cracked, and a small piece had broken off. A hole where a pin used to engage to drive the curtain had turned into a notch, and the whole mechanism ceased to work.
The part likely cracked due to metal fatigue. This camera model's flash sync speed is 1/250 s, which means that the trailing edge of the first curtain and the leading edge of the second curtain must speed up from a standstill, traverse the 24 mm height of the sensor, slow down, and come to a stop, all in less than 4 ms. This requires an acceleration of at least 6000 m/s², or 611 g. The forces acting on those paper-thin shutter blades must be considerable.
Shutter Failure
After about half a million exposures the shutter in my DSLR called it quits. A part of the linkage that holds the blades of one of the shutter curtains together as they move had cracked, and a small piece had broken off. A hole where a pin used to engage to drive the curtain had turned into a notch, and the whole mechanism ceased to work.
The part likely cracked due to metal fatigue. This camera model's flash sync speed is 1/250 s, which means that the trailing edge of the first curtain and the leading edge of the second curtain must speed up from a standstill, traverse the 24 mm height of the sensor, slow down, and come to a stop, all in less than 4 ms. This requires an acceleration of at least 6000 m/s², or 611 g. The forces acting on those paper-thin shutter blades must be considerable.