This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (September 2010) In film, the second unit is a team that shoots subsidiary footage for a motion picture. Its work is distinct from that of the first unit, which shoots all scenes involving principal actors. Second unit footage typically includes establishing shots, close-ups, inserts, and cutaways.

The work of second units should not be confused with multicamera setups filming the same scene simultaneously run by the first unit. Large productions may have multiple second units, called “additional second units”, never third or fourth unit. Role Second units exist to allow a film's titular director and principal talent to work more effectively and economically, shooting only that footage required of them.

In addition to shooting establishing shots, close-ups, inserts, and cutaways Second units also film in locations too expensive or dangerous to send the first unit to. Often this involves stunts and close-ups with body doubles, making continuity between the two units' work challenging.

The second unit films inserts, occasionally overseen by an editor who knows which shots are required for continuity. Directors The second unit has its own director and cinematographer. Second unit director is stepping stone for aspiring directors to gain experience, and is considered above the post of assistant director. Second unit directors who have gone on to become fully-fledged film directors include Barry Sonnenfeld (The Addams Family), John Glen (On Her Majesty's Secret Service), and Ron Shelton (Bull Durham).

As Second units oversee many dialogue-free scenes with stunts and special effects in action movies, the job of stunt coordinator is often combined with that of second unit director. As a result, many second unit directors are former stunt coordinators, including Vic Armstrong (Bear Island, Mission: Impossible III), Simon Crane (Frankenstein (1994), X-Men: The Last Stand), and Terry J. Leonard (Big Wednesday, The Forgotten).

Some second unit directors make such work their careers. A notable example is Michael D. Moore, who shot the desert chase sequence in Raiders of the Lost Ark and has worked on more than sixty films, including The Man Who Would Be King, Indiana Jones and the Temple of Doom, and Indiana Jones and the Last Crusade. References Interview with David Ellis, second unit director of The Matrix Reloaded - retrieved on April 7, 2005