Not any video camera will work. With this, a sensor picks up the flash of the gun from a distance. That starts the clock. A videotape is made of the race finish, and the finish times are recorded on the tape. Not the greatest, but it does the job.
Many colleges use it as a backup system.
In Michigan, this system is owned by Grosse Ile High School. It is also used by Calvin, Hope, Saginaw Valley, and used as a backup by Hillsdale and Western Michigan.