The axis crossing (English: 180-degree rule) – rule for spatial continuity in film, where the camera should not cross an imaginary line between two characters to avoid confusion.
Definition
Crossing the Line (German: Achsensprung) refers to an editing error where the camera crosses the imaginary axis of action between two actors. This causes the characters' gazes to appear reversed to the viewer, leading to a loss of spatial orientation.
The 180-Degree Rule
The axis of action is an imaginary line that runs through the main characters of a scene – typically between two people conversing. The 180-degree rule states that all camera positions within a scene must remain on the same side of this axis.
If this rule is broken, the characters will suddenly appear to be looking or moving in the opposite direction. The viewer loses spatial orientation within the scene.
When is Crossing the Line Permitted?
Although crossing the line is classically considered an error, experienced filmmakers use it intentionally as a stylistic device:
- Disorientation: In fight or chase scenes, a controlled crossing of the line can convey chaos.
- Psychological Effect: Unease, confusion, or a turning point in the plot.
- Stylistic Choice: The Nouvelle Vague and modern auteur cinema deliberately break the rule.
Avoiding it in Practice
On set, there are several techniques to avoid unintentional crossings of the line:
- Clearly define the axis before shooting begins.
- Carry the axis with camera movements.
- Use a neutral shot (on the axis) as a transition.
- In editing: Use cutaways or inserts as a "bridge."
Related Terms
Crossing the line is closely related to the concept of continuity and the shot-reverse-shot technique. While the axis of gaze concerns the actors' eye lines, the axis of movement refers to the direction of movement within the frame.