The split screen is a technique used to depict multiple scenes occurring simultaneously. It is often employed to show both sides of a phone conversation.
In 24, the split screen technique receives thorough use due to the show's real time format and simultaneous multiple plot lines. A split screen showcasing multiple characters and locations is always featured along with the ticking clock on each return from a commercial break (the act-in clock). Additionally, the final few minutes of almost every episode are prefaced by a split screen, often with urgent music, to update viewers on the status of each major character and plotline as the hour ends.
Split screen formatting
Though all seasons of 24 have been filmed in widescreen, for Seasons 1-3 the split screen was restricted to 4:3 ratio and appeared only in the center of the screen with pillarboxing so it would appear fully in frame when the program was presented cropped for non-widescreen televisions. Starting with Season 4, split screens have been formatted for widescreen presentation. Also, the digital clock before and after each commercial break beginning with Season 4 has been kerned together as closely as possible, so that 1's no longer occupy the same amount of space as other digits. As a result of this, the clocks shown in later seasons generally avoid times that require either a 0 changing to a 1 or a 1 to a 2, although these sometimes occur, happening more frequently in Live Another Day.
For Live Another Day, the clock appears in a different color to match the season's slightly new lettering. Additionally, for single-digit times, the 0 before the hour digit has been omitted.
Split screen deviations
Absence of final split screen
Due to the expected nature of the split screen in 24, the lack of a split screen can be used to create intensity, as was the case leading up to Ryan Chappelle's execution during "Day 3: 6:00am-7:00am." Without the split screen to signal the end of the episode approaching, it would be easy to hold out hope of saving Chappelle's life, until the clock signaled otherwise. While the final split screen sequence was used in virtually every episode during the early seasons, later on it became omitted more often. Episodes that do not feature a final split screen are:
These lacked split screens for dramatic purposes. In the case of "Day 4: 10:00pm-11:00pm" for example, the split screen was excluded so as not to interrupt Jack's attempt to dissuade Anderson from attacking Air Force One. In the case of the "series finale", this was to heighten the emotional drama of the final moments of the show as well as between Chloe and Jack.
In "Day 1: 3:00am-4:00am" and "Day 1: 6:00am-7:00am," the act-in clocks are directly superimposed over the various split screen panels, with no black background. These are the only two episodes in which this occurs.
The act-in clock at 6:54am in "Day 1: 6:00am-7:00am" is both the shortest in the series' history and the only to have no split screen panels around it.
Giant episode closers
On only two occasions has an episode not closed with a final scene. In "Day 3: 9:00am-10:00am" and "Day 5: 12:00am-1:00am" the split screen sequences were followed immediately by the final clock, without the expected final scene. Both instances showcased more panes, cutting in one after the other during the split screen, than any other episode. Jack Bauer and Chloe O'Brian are the only characters to have been featured on both giant episode closers.
Background information and notes
- Several episodes of the British television series Spooks (known as MI-5 in the United States) perform split screens in a similar fashion to 24 (see example), though every case does not involve a clock in the middle of the screen, as the series is not interpreted in real-time. In an audio commentary from the series pilot episode, the fact that the split screens from both shows were similar was unintentional; at the time when the episode was in post-production, 24 did not appear in the UK yet.
- A similar split screen technique was also used regularly in Burn Notice, another spy-themed series.
- The longest final split screen is 51 seconds at the end of Redemption. Second is "Day 8: 2:00pm-3:00pm" at 40 seconds. Third is "Day 8: 10:00am-11:00am" at 39 seconds. Fourth is "Day 8: 11:00am-12:00pm" at 36 seconds. Tied for fifth are "Day 1: 12:00pm-1:00pm" and "Day 8: 4:00am-5:00am" at 33 seconds.