Clapper loader

A clapper loader, second assistant camera (2nd AC) or simply loader, is part of a film crew, whose main functions are that of loading the raw film stock into camera magazine, 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 name "clapper loader" tends to be used in the United Kingdom and Commonwealth, while second assistant camera tends to be favoured in the United States, but the job is essentially the same whichever title is used. The specific responsibilities and division of labor within the department will almost always vary depending on the circumstances of the shoot. 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... full article at wikipedia