Split screen (video production)

In film and video production, split screen is the visible division of the screen, traditionally in half, but also in several simultaneous images, rupturing the illusion that the screen's frame is a seamless view of reality, similar to that of the human eye. There may or may not be an explicit borderline. Until the arrival of digital technology, a split screen in films was accomplished by using an optical printer to combine two or more actions filmed separately by copying them onto the same negative, called the composite.
In filmmaking split screen is also a technique that allows one actor to appear twice in a scene. The simplest technique is to lock down the camera and shoot the scene twice, with one "version" of the actor appearing on the left side, and the other on the right side. The seam between the two splits is intended to be invisible, making the duplication seem realistic.
Popularisation.
Several studio-made films in the 1960s popularized the use of split screen. They include "Indiscreet" (1958), John Frankenheimer's "Grand Prix" (1966), Richard Fleischer's "The Boston Strangler" (1968), Norman Jewison's "The Thomas Crown Affair" (1968), "Airport" (1970), "Woodstock" (1970), "The Andromeda Strain" (1971), "Sisters" (1972), "Carrie" (1976) and "More American Graffiti" (1979).
In "Indiscreet", the technique was famously used to bypass the censors and allow Cary Grant and Ingrid Bergman to be in bed together, and even to appear to pat her on the bottom.
Influences.
An influential arena for the great split screen movies of the 1960s were two world's fairs - the 1964 New York World's Fair, where Ray and Charles Eames had a 17-screen film they created for IBM's "Think" Pavilion (it included sections with race car driving) and the 3-division film "To Be Alive," by Francis Thompson, which won the Academy Award that year for Best Short. John Frankenheimer made "Grand Prix" after his visit to the 1964 New York World's Fair. The success of these pavilions further influenced the 1967 Universal exhibition in Montreal, commonly referred to as Expo 67, where multi-screen highlights included "In the Labyrinth", hailed by "Time" magazine as a "stunning visual display," their review concluding: "such visual delights as Labyrinth ... suggest that cinema—the most typical of 20th century arts—has just begun to explore its boundaries and possibilities," as well as "A Place to Stand", which displayed Christopher Chapman's pioneering "multi-dynamic image technique" of shifting multiple images. Directors Norman Jewison and Richard Fleischer conceived their ambitious split-screen films of 1968 after visiting Expo '67.
It's also common to use this technique to simultaneously portray both participants in a telephone conversation, a long-standing convention which dates back to early silents, as in Lois Weber's triangular frames in her 1913 "Suspense", and culminating in "Pillow Talk", where Doris Day and Rock Hudson share a party line. So linked to this convention are the Doris Day/Rock Hudson movies that "Down With Love", the only slightly tongue-in-cheek homage, used split screen in several phone calls, explicitly parodying this use. In the 1971 Emmy Award-winning TV movie "Brian's Song" which portrays the story of former Chicago Bears running backs Brian Piccolo and Hall of Famer Gale Sayers, it's the night after Piccolo's second surgery and Piccolo (James Caan) is talking to Sayers (Billy Dee Williams) on the phone. There is a diagonal split screen from upper left corner to lower right corner (Piccolo on the right side and Sayers on the left). The BBC series "Coupling" made extensive use of split screen as one of several techniques that are unconventional for TV series, often to a humorous effect. One episode, 'Split', was even named after the use of the effect. The acclaimed Fox TV series "24" used split-screen extensively to depict the many simultaneous events, enhancing the show's real-time element as well as connecting its multiple storylines.
An unusual and revolutionary use of split screen as an extension to the cinematic vocabulary was invented by film director Roger Avary in "The Rules of Attraction" (2002) where two separate halves of a split screen are folded together into one seamless shot through the use of motion control photography. The much acclaimed shot was examined and detailed in Bravo Television's "Anatomy of a Scene".
Digital technology.
The arrival of digital video technology has made dividing the screen much easier to accomplish, and recent digital films and music videos have explored this possibility in depth. Sometimes the technique is used to show actions occurring simultaneously; "Timecode" (2000), by Mike Figgis, is a recent example where the combination is of four real time digital video cameras shown continuously for the duration of the film. Split-screen can also be used to the extent that it becomes part of the narrative structure of a film, as in "The Boston Strangler".
Usage.
In films.
Early use of split screen can be seen in the Russian silent film "The Queen of Spades" (1916), directed by Yakov Protazanov, where one screen depicts reality and the other a character's inner desires. This technique has been used to portray twins in such films as "Wonder Man" (1945), "The Dark Mirror" (1946), "The Parent Trap" (both the 1961 original and the 1998 remake), and "Adaptation" (2002). In the 1961 version of "The Parent Trap", conversations between the twins were simulated by filming the actress (Hayley Mills) as she stood at the left of the frame facing right, then filming her again, standing at the right and facing left. The negative of the first action was placed into a printer and copied onto another negative, the composite, but this other negative was masked so that only the right part of the original picture is copied. Then the composite was rewound and the negative of the second action was copied onto the right side of each frame. On this second pass, the left side was masked to prevent double exposure. This technique is then carefully hidden by background lines, such as windows, doors, etc. to disguise the split.
Hans Canosa's 2005 film "Conversations with Other Women" made extensive use of split screens. "Conversations" juxtaposed shot and reverse shot of two actors in the same take, captured with two cameras, for the entire movie. The film was designed to enlist the audience as perceptual editors, as they can choose to watch either character act and react in real time. While the shot/reverse shot function of split screen comprises most of the running time of the film, the filmmakers also used split screen for other spatial, temporal and emotional effects. "Conversations"' split screen sometimes showed flashbacks of the recent or distant past juxtaposed with the present; moments imagined or hoped by the characters juxtaposed with present reality; present experience fractured into more than one emotion for a given line or action, showing an actor performing the same moment in different ways; and present and near future actions juxtaposed to accelerate the narrative in temporal overlap.
By filmmakers.
The visionary French director, Abel Gance, used the term "Polyvision" to describe his three-camera, three-projector technique for both widening and dividing the screen in his 1927 silent epic, "Napoléon". The filmmaker Brian De Palma has incorporated split screens into many of his films, most notably in "Sisters" (1973) and they have since become synonymous with his filmmaking style (Specifically 1981's "Blow Out" and 1998's "Snake Eyes").
In technology.
The "Interactive Olaf" bonus feature from the DVD release of "Lemony Snicket's A Series of Unfortunate Events" shows Jim Carrey's makeup tests from the movie in a four-way split-screen. Viewers can split the audio by selecting which one to listen to, then pressing "ENTER" on their DVD remote. The split screen has also been simulated in video games. Most notably "Fahrenheit" where it is used to allow a player to keep track of multiple simultaneous elements relevant to the gameplay.
In music video.
A number of music videos have made creative use of split screen presentations. In Michael Jackson's "Billie Jean" video a number of freeze frames are shown in split screen. Video and film director Michel Gondry has made extensive use of split screen techniques in his videos. One notable example is "Sugar Water" - Cibo Matto (1996), where one side of the screen shows the video played normally, and the other side shows the same video played backwards. Through careful and creative staging the two sides appear to interact directly - passing objects from side to side and visually referencing each other. The music video for "Doo Wop (That Thing)" by Lauryn Hill was filmed using a split screen technique, the video features Lauryn, performing the song at block parties in two different eras: the mid-1960s (The year 1967 is shown on the left of the video) and the late-1990s (The year 1998 is shown on the right).
In television.
The split screen has also been used extensively in television programs. Newscasts often show two reporters in a split screen frame. The sitcom "That '70s Show", Nickelodeon teen sitcom "Drake & Josh", Disney Channel teen sitcom "Lizzie McGuire", USA Network's "Burn Notice" and Fox's "24" made extensive use of split screens. It is sometimes used in game shows to show two contestants simultaneously, and on cable news shows, when participants in a discussion are in different locations.
Split screens are frequently used in motor racing, especially during safety car pit stops in the IndyCar Series and NASCAR, where four way splits are used, most often with three leading cars or trucks' pit stops shown on the left and a shot of the pit exit (where restart order is determined after pit stops) on the right, with some featuring just four different cars or trucks making pit stops. Often these pit stops can change the entire outcome of a race. In sports, an instant replay, highlights package, or featurette on a specific subject relating to the play may be shown in a corner while the main play is happening.
In 2019, Snapchat's original content arm, Snap Originals, released a series called 'Two Sides', which followed a young couple as they navigated a breakup, told from both perspectives at the same time. Season Two and Season Three will be released in 2021. 
Split screens are sometimes used during commercial breaks, as in ESPN's "Side-By-Side" coverage of racing, where one side of the screen shows race footage and the other shows advertising. This allows commercial to be shown while not interrupting coverage of race action.
Split screens are also common in advertising, often to show comparison.