Editing I: continuity editing

A film is usually made of hundreds or thousands of shots. Editing is the craft of selecting shots and joining them, deciding what follows what, for how long, and with what kind of transition. It is sometimes called the invisible art, because the most widespread editing system is designed so that viewers do not notice it at all. This lesson explains that system, continuity editing, which developed in American cinema in the 1910s and became the international default for narrative film. Lesson 7 looks at alternatives: montage, rhythm, jump cuts and the long take.

What editing controls

Editing controls four kinds of relationship between shots, a framework widely used in film studies.

• Graphic relations: how the shapes, colours, movements and compositions of two shots relate. A graphic match links shots through similar shapes or movement.
• Rhythmic relations: how long each shot lasts and the pattern of durations, which create pace.
• Spatial relations: how editing constructs a sense of space, connecting places that may be filmed miles or months apart.
• Temporal relations: how editing orders events and compresses or expands time.

Every cut involves all four, even if the editor's main concern is one. In continuity editing, the dominant goal is clarity of space and time so that the story flows smoothly.

Transitions

Most shots are joined by a straight cut, an instantaneous change from one shot to the next. Other transitions carry conventional meanings.

The 180-degree rule

The foundation of continuity editing is the 180-degree system. Imagine a line, called the axis of action, running through the main characters or the direction of movement in a scene. The camera stays on one side of that line, within a half-circle of 180 degrees. As long as it does, characters keep consistent screen directions: the person on the left stays on the left and looks right, the person on the right looks left, and movement continues in the same direction from shot to shot.

If the camera crosses the line, the characters appear to swap sides and look in the same direction, which can confuse viewers about where people are. Filmmakers who want to cross the line usually do so with a shot that moves across it on screen, a shot directly along the axis, or a cutaway that resets our orientation.

Establishing and analytical editing

A classical continuity scene often follows a pattern.

• An establishing shot, usually a long shot, shows the space and the characters' positions.
• The scene is then broken down into closer shots, called analytical editing: medium shots, over-the-shoulder shots, close-ups.
• A re-establishing shot may return to a wider view when characters move or new ones enter.

This pattern gives viewers a mental map of the space so that closer shots never confuse them.

Shot/reverse-shot and eyeline match

Conversations in continuity style are usually edited as shot/reverse-shot: a shot of one character, then a shot of the other from the opposite angle on the same side of the axis, alternating. Over-the-shoulder framings include part of the listener in the foreground, which reinforces the spatial relation.

An eyeline match cuts from a character looking at something offscreen to a shot of what they are looking at. The viewer infers that the second shot shows what the character sees, even if the two shots were filmed separately. Eyeline matches are the basis of point-of-view editing, described in Lesson 2.

Match on action

A match on action cuts from one shot to another in the middle of a movement, so that the movement appears to continue across the cut. A character reaches for a door handle in a long shot; the next shot is a close-up of the hand turning the handle. The motion carries the eye across the cut and hides it. Editors often cut on movement for exactly this reason.

Other continuity devices include matching props, costumes and lighting between shots (the job of the script supervisor during shooting) and keeping directions of entrances and exits consistent: a character who exits frame right should usually enter the next shot from frame left if they are moving in the same direction.

Cutaways, inserts and crosscutting

• A cutaway shows something outside the main action, such as a clock or a bystander, often to cover a jump in time or a continuity problem.
• An insert is a close shot of a detail within the scene, such as a letter or a phone screen, that gives important information.
• Crosscutting (parallel editing) alternates between two or more lines of action happening in different places, usually at the same time. Early American filmmaker D. W. Griffith made crosscutting famous for last-minute rescues; it remains standard in thrillers and action films to build suspense.

Why continuity editing feels invisible

Continuity editing works because it exploits how viewers perceive and infer. We assume that shots joined together are connected in space and time unless told otherwise. Cuts timed to movement, eyelines and dialogue pass almost unnoticed. Cognitive film researchers have found that viewers often fail to notice cuts that follow continuity principles, while they readily notice jarring ones. This invisibility is a style, not a neutral recording of reality, and it has costs and benefits. It makes stories easy to follow, but it can also hide how much the film constructs what we see.

Continuity on set and in post

Continuity is maintained during shooting and built in editing.

In Canada, picture editors on many productions are represented by the Directors Guild of Canada, which includes picture and sound editors in several regions, and the Canadian Cinema Editors organization promotes the craft. Script supervisors keep continuity notes on set so that editors can match action, props and eyelines later.

Coverage and the editor's choices

On most narrative productions, each scene is filmed several times from different set-ups, a practice called coverage. A typical dialogue scene might be covered with a wide master shot of the whole action, medium shots of each character, over-the-shoulder shots and close-ups, plus inserts of important objects. The editor then chooses which shot to use for each moment, which take of each shot, and exactly where to cut. These choices shape performance and emphasis. An editor can hold on a listener's reaction rather than the speaker, cut away just before a line lands, or let a pause run long to build tension.

Because the same footage can be cut in many ways, editing is sometimes described as the final rewrite of a film. Editors often say they cut for emotion first, story second and rhythm third, and only then worry about perfect continuity. When analyzing a scene, ask not only how the shots are joined but why the editor might have chosen this shot at this moment. Whose reaction are we shown? What are we prevented from seeing? How long does the editor make us wait?