The Mechanics of Subtitling: Why Audiovisual Translation is Unique

Audiovisual Translation (AVT) operates under a unique set of constraints that distinguish it from standard text translation.
While a reader can linger over a page, a subtitle must be processed in the few seconds it appears on screen.
Any translations must also take into account the visuals on-screen, in terms of puns or spoilers.

Professional subtitling is built on several key technical foundations to ensure the audience remains immersed in the visuals:

• Reading Speed (CPS): To prevent text from vanishing too quickly, the industry uses Characters Per Second (CPS) as a primary metric.
  For most English-speaking audiences, subtitles are calibrated to a speed of 15–20 characters per second,
  allowing the brain to process the text comfortably without missing the action.

• Space Constraints: On-screen "real estate" is limited. Subtitles are typically restricted to a certain number of characters per line
  (usually between 42 and 50 characters, depending on use-case) and are capped at two lines to avoid obstructing the cinematography or overwhelming the viewer.

• Duration & Timing: For a subtitle to be properly registered by the eye, it requires a minimum duration (often one to two seconds).
  Timing is synchronized right down to the frame with the rhythm of the speech and the scene's natural flow.

• Shot Changes: Crossing a camera cut with a subtitle can be visually jarring.
  Aligning subtitle "in-and-out" points with shot changes creates a seamless viewing experience that feels integrated with the film’s editing.

• Italics: In subtitling, italics are a specific functional tool rather than a stylistic choice.
  They are used to differentiate off-screen voices (such as a narrator, a voice on a telephone, or a character in another room)
  and to distinguish song lyrics or media within the scene from the main dialogue.

• Single vs Dual Tracks: Handling simultaneous information, such as dialogue and “on-screen text” (OSTs) or “forced narratives” (FNs), is one of the most complex aspects of subtitling.
  While some formats allow for vertical separation (OSTs at the top of the screen, dialogue on the bottom), most modern global platforms require a single-track delivery.
  This requires the expertise to meticulously intersperse and time both elements so the viewer can follow the story without being overwhelmed.