best boy

In a film crew, there are two kinds of best boy: best boy electric (also known as the assistant chief lighting technician) and best boy grip (also known as the 2nd company grip). They are assistants to their department heads, the gaffer (in charge of electricals) and the key grip (lighting and rigging), respectively. In short, the best boy acts as the foreman for the department. A woman who performs these duties may be called best girl.