A gun camera is a camera used to automatically record images of the target when a Viper pilot's guns are fired. A Raptor has a gun camera with manual control (Margaret "Racetrack" Edmondson tells Skulls to record the Resurrection Hub with the gun camera ("Guess What's Coming to Dinner")).
Starbuck's gun camera video is reviewed, but fails to show the Heavy Raider that she claimed to have fired at ("Maelstrom").