The function of the first and second assistant director is to assist the director make sure that the shoot goes as planned. Both have exactly the same amount of responsibility and control of the set. Below is really a breakdown of a few of the key tasks performed by the first and second director.
The first assistant director acts as the right-hand man (or woman) of the director. There are instances when the responsibilities of the first director is nearly exactly the same using the director. Usually, the first director works using the actors throughout scene rehearsals that includes blocking, and he or she also works using the extras to make certain that they know what their function is within the scene. They’re also responsible for checking to make certain that the movie is being filmed at its expected pace. If the shoot starts lagging behind its projected production schedule, it’s most likely go over budget, causing all sorts of headaches for the producer. Keeping the schedule on track is the responsibility of the first assistant director. To that end, he or she is also tasked with making certain the cast and crew signs in on time, and to usually keep the shoot rolling along at a great pace.
It also tends to be the first assistant director who calls out “action” and “cut” (also as a host of other terms that signal the syncing up of the sound and picture, plus cues meant for the editor). By handling the technicalities, the film director can now concentrate on the action shot for a particular scene.
To ensure that orders of the first assistant director are carried out is the job of the second assistant director and he or she reports to the first assistant director. The “Second” is also responsible for working using the film’s production coordinator to produce daily call sheets, which list when crew, actors, and extras are expected on set, also as any transportation needs. The Second is also responsible for the actors as soon as they get on set, escorting them to hair, makeup, and wardrobe, and addressing any concerns or requests they might have. The Second gets the actors to the set according to schedule as soon as the actors are camera ready.
Somewhat surprisingly, because of their titles, first and second assistant directors rarely go on to become actual film directors nowadays. Because most of their responsibilities revolve around production, the first and second assistant director often wind up within the production department.