In most arenas, professional photographers have access to the built in strobe lights. You can notice (if you pay attention) to the flashing of the lights when p

In most arenas, professional photographers have access to the built in strobe lights. You can notice (if you pay attention) to the flashing of the lights when professional is snapping pictures. They typically have little antennas on the top of the camera, so the flash is automated with the shutter. This is most noticeable at hockey or basketball games, where the arena is much smaller and the lights are closer.