We have seen many vision based tracking system but this is one technology that amazes me.
Professor Masatoshi Ishikawa from the University of Tokyo has developed a pan-tilt unit for a 1,000Hz camera for tracking the ball but instead of moving the camera, 2 mirrors are used to reduce the weight of the system for it to perform such agile and high speed motion. This is explained on their site.
The following tracking is also done in the lab but with the camera mounted on the pan-tilt unit. The weight of the moving camera does matter when it concerns high speed tracking.