Second Assistant Camera
1. A clapper loader, or second assistant camera (2nd AC) is part of a film crew, whose main functions are that of loading the raw film stock into camera magazines, operating the clapperboard (slate) at the beginning of each take, marking the actors as necessary, and maintaining all records and paperwork for the camera department.
The clapper loader typically has a very high responsibility level on any given set, because they are more or less the only person on set who directly and physically oversees the state of the undeveloped negative. The loader is the only person who actually handles the negative between the manufacturer and the laboratory, and thus can easily render an entire day’s work useless if the film is handled improperly. Additionally, the loader usually is in charge of keeping all records with regard to the film stock from when it is received until when it is sent out to the lab