MOS (film)
Encyclopedia
MOS is a standard filmmaking
jargon
abbreviation
, used in production reports to indicate an associated film segment has no synchronous audio track
. It stands for "Motor Only Sync" or "Motor Only Shot".
Omitting sound recording from a particular shot can save time and relieve the film crew
of certain requirements, such as remaining silent during a take, and thus MOS takes are common on film shoots, most obviously when the subjects of the take are not speaking or otherwise generating useful sound.
In post-production
, an MOS take may be combined with miscellaneous sounds recorded on location, the musical soundtrack
, voice-over
s, or sound effect
s created by a foley artist
.
When sound recording reached the point where the sound was recorded on a synchronized but separate piece of media (such as 35mm film
, audio tape, or other media) a method of keeping the recording media and camera film "in sync" was needed. The solution was to use a special form of motor which has multiple "windings" in it, and which can be connected to another identical motor in such a way that turning one motor a certain distance will turn the other motor exactly the same distance. The motors did not have to be close together, and, with appropriate circuitry, did not have to be of the same size or power. These motors were called Selsyn (self synchronous) motors. A system was created where a single sound recording room could be connected to any of the stages on a studio lot (you can still see the connection points on some of the oldest stages.) The sound mixer (sound man) on stage connected the control panel to the recording room
and the camera. There was a Selsyn motor on the camera and it was linked to a matching selsyn motor on the sound recording equipment at another point on the studio lot
.
In order to use this system, the sound mixer used an intercom
to the sound recordist to tell him to "roll", or start the system. Since this was a very mechanical system, it took some time to start and get up to proper speed. When proper speed and synchronization was reached, the recordist would use the intercom to announce, "Speed" and the Sound Mixer would relay that to the director
and crew on the stage. The expression is still used, but now simply means, "Sound is recording".
It was the recordist who actually started and stopped the camera motor (the camera operator
had a switch to ensure that the camera didn't roll at an inopportune time such as loading, replacing lenses, etc., and to stop it if something went amiss). The actual power source for the camera motor was in the sound booth.
When a shot was planned that did not require sound, the sound mixer would ask the recordist to "roll the motor only". The recordist would start the camera motor without starting the matching "sound" motor and electronics. The procedure acquired the name "motor only shot", thus MOS.
According to this theory, a German director, recently transplanted to Hollywood (probably Ernst Lubitsch
, but possibly Fritz Lang
), was asked by a script supervisor
how he would like to shoot the next scene of the day. The director responded "Mit out Sprechen!", and so this was noted as a joke on the production reports and the camera slates for the shot. In The Screenwriter's Bible, David Trottier credits the term to Austrian director Erich von Stroheim
, who allegedly would tell his crew "Ve'll shoot dis mid out sound." Many have also referred to MOS as "Motion On Screen."
Documentary, news and reality shows have added to the meaning of MOS to mean "Man On Street" which are random interviews from the public.
Filmmaking
Filmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...
jargon
Jargon
Jargon is terminology which is especially defined in relationship to a specific activity, profession, group, or event. The philosophe Condillac observed in 1782 that "Every science requires a special language because every science has its own ideas." As a rationalist member of the Enlightenment he...
abbreviation
Abbreviation
An abbreviation is a shortened form of a word or phrase. Usually, but not always, it consists of a letter or group of letters taken from the word or phrase...
, used in production reports to indicate an associated film segment has no synchronous audio track
Sound film
A sound film is a motion picture with synchronized sound, or sound technologically coupled to image, as opposed to a silent film. The first known public exhibition of projected sound films took place in Paris in 1900, but decades would pass before sound motion pictures were made commercially...
. It stands for "Motor Only Sync" or "Motor Only Shot".
Omitting sound recording from a particular shot can save time and relieve the film crew
Film crew
Television crew positions are derived from those of film crew positions.A film crew is a group of people hired by a production company for the purpose of producing a film or motion picture. Crew are distinguished from cast, the Actors who appear in front of the camera or provide voices for...
of certain requirements, such as remaining silent during a take, and thus MOS takes are common on film shoots, most obviously when the subjects of the take are not speaking or otherwise generating useful sound.
In post-production
Post-production
Post-production is part of filmmaking and the video production process. It occurs in the making of motion pictures, television programs, radio programs, advertising, audio recordings, photography, and digital art...
, an MOS take may be combined with miscellaneous sounds recorded on location, the musical soundtrack
Soundtrack
A soundtrack can be recorded music accompanying and synchronized to the images of a motion picture, book, television program or video game; a commercially released soundtrack album of music as featured in the soundtrack of a film or TV show; or the physical area of a film that contains the...
, voice-over
Voice-over
Voice-over is a production technique where a voice which is not part of the narrative is used in a radio, television production, filmmaking, theatre, or other presentations...
s, or sound effect
Sound effect
For the album by The Jam, see Sound Affects.Sound effects or audio effects are artificially created or enhanced sounds, or sound processes used to emphasize artistic or other content of films, television shows, live performance, animation, video games, music, or other media...
s created by a foley artist
Foley artist
Foley is the reproduction of everyday sounds for use in filmmaking. These reproduced sounds can be anything from the swishing of clothing and footsteps to squeaky doors and breaking glass. The best foley art is so well integrated into a film that it goes unnoticed by the audience. It helps to...
.
Origins of the term
There are many theories regarding the source of the abbreviation "MOS".When sound recording reached the point where the sound was recorded on a synchronized but separate piece of media (such as 35mm film
Sound-on-film
Sound-on-film refers to a class of sound film processes where the sound accompanying picture is physically recorded onto photographic film, usually, but not always, the same strip of film carrying the picture. Sound-on-film processes can either record an analog sound track or digital sound track,...
, audio tape, or other media) a method of keeping the recording media and camera film "in sync" was needed. The solution was to use a special form of motor which has multiple "windings" in it, and which can be connected to another identical motor in such a way that turning one motor a certain distance will turn the other motor exactly the same distance. The motors did not have to be close together, and, with appropriate circuitry, did not have to be of the same size or power. These motors were called Selsyn (self synchronous) motors. A system was created where a single sound recording room could be connected to any of the stages on a studio lot (you can still see the connection points on some of the oldest stages.) The sound mixer (sound man) on stage connected the control panel to the recording room
Recording studio
A recording studio is a facility for sound recording and mixing. Ideally both the recording and monitoring spaces are specially designed by an acoustician to achieve optimum acoustic properties...
and the camera. There was a Selsyn motor on the camera and it was linked to a matching selsyn motor on the sound recording equipment at another point on the studio lot
Backlot
A backlot is an area behind or adjoining a movie studio, containing permanent exterior buildings for outdoor scenes in filmmaking or television productions, or space for temporary set construction....
.
In order to use this system, the sound mixer used an intercom
Intercom
An intercom , talkback or doorphone is a stand-alone voice communications system for use within a building or small collection of buildings, functioning independently of the public telephone network. Intercoms are generally mounted permanently in buildings and vehicles...
to the sound recordist to tell him to "roll", or start the system. Since this was a very mechanical system, it took some time to start and get up to proper speed. When proper speed and synchronization was reached, the recordist would use the intercom to announce, "Speed" and the Sound Mixer would relay that to the director
Film director
A film director is a person who directs the actors and film crew in filmmaking. They control a film's artistic and dramatic nathan roach, while guiding the technical crew and actors.-Responsibilities:...
and crew on the stage. The expression is still used, but now simply means, "Sound is recording".
It was the recordist who actually started and stopped the camera motor (the camera operator
Camera operator
A camera operator or cameraman is a professional operator of a film or video camera. In filmmaking, the leading cameraman is usually called a cinematographer, while a cameraman in a video production may be known as a television camera operator, video camera operator, or videographer, depending on...
had a switch to ensure that the camera didn't roll at an inopportune time such as loading, replacing lenses, etc., and to stop it if something went amiss). The actual power source for the camera motor was in the sound booth.
When a shot was planned that did not require sound, the sound mixer would ask the recordist to "roll the motor only". The recordist would start the camera motor without starting the matching "sound" motor and electronics. The procedure acquired the name "motor only shot", thus MOS.
Alternate origins
A popular (presumed to be mythical) origin theory is that MOS stands for broken-English "Mit out sound", that is, "Without sound" as a 1920s German-émigré director might have said it.According to this theory, a German director, recently transplanted to Hollywood (probably Ernst Lubitsch
Ernst Lubitsch
Ernst Lubitsch was a German-born film director. His urbane comedies of manners gave him the reputation of being Hollywood's most elegant and sophisticated director; as his prestige grew, his films were promoted as having "the Lubitsch touch."In 1947 he received an Honorary Academy Award for his...
, but possibly Fritz Lang
Fritz Lang
Friedrich Christian Anton "Fritz" Lang was an Austrian-American filmmaker, screenwriter, and occasional film producer and actor. One of the best known émigrés from Germany's school of Expressionism, he was dubbed the "Master of Darkness" by the British Film Institute...
), was asked by a script supervisor
Script supervisor
A script supervisor is a member of a film crew responsible for maintaining the motion picture's internal continuity and for recording the production unit's daily progress in shooting the film's screenplay...
how he would like to shoot the next scene of the day. The director responded "Mit out Sprechen!", and so this was noted as a joke on the production reports and the camera slates for the shot. In The Screenwriter's Bible, David Trottier credits the term to Austrian director Erich von Stroheim
Erich von Stroheim
Erich von Stroheim was an Austrian-born film star of the silent era, subsequently noted as an auteur for his directorial work.-Background:...
, who allegedly would tell his crew "Ve'll shoot dis mid out sound." Many have also referred to MOS as "Motion On Screen."
Documentary, news and reality shows have added to the meaning of MOS to mean "Man On Street" which are random interviews from the public.