Designed for increased durability and to reduce dust generated within the camera, the electronically controlled mechanical shutter of the EOS-1Ds Mark III is capable of 300,000 cycles — the highest rating of any Canon camera. This rugged durability is matched by a lightning quick shutter release lag time of only 55ms and a viewfinder blackout time of 80ms, assuring rapid response in fast-moving situations. Available shutter speeds range from 30 seconds to 1/8000 second with a fast flash synch speed of 1/250 second. Two synch terminals are available, one for Canon Speedlites and another for non-Canon flash units.