Why Editing Works

Videos: Spiderman2.mov, EditingRules.mov

BC: Art and Visual Perception, Fall 2006

by Brian Retchless


A hand grabs a bag. A man squints. A gun is fired. A man flies against the wall, his face contorted in pain. A woman walks across an empty corridor. A woman kicks something on the ground and walks away.

This is a movie. Or rather, this is a literal interpretation of what we see when we watch an edited motion picture. But this isn't how we experience it -- far from it. When we visit our local multiplex we sit down and experience a story. We don't focus on the thousands of separate images that make up the story but instead (if the film is well-crafted) we get lost in the story, taking for granted the ever-roaming camera that offers us a plethora of views that we would never be able to experience in our own lives.

Film editing is an under-appreciated art. The ultimate goal of the editor is to make the editing invisible, and as such, we often only notice editing when it is, well, less than satisfactory. But how is this even possible? The whole thing is a bit mind-boggling, that these various pieces could come together to form some cohesive whole. "The mysterious part of it is that the joining of those pieces... actually does seem to work, even though it represents a total and instantaneous displacement of one field of vision with another, a displacement that sometimes also entails a jump forward or backward in time as well as space." (Murch, 5) It would seem as though nothing in our day-to-day life has prepared us for the rapid barrage of imagery that is a modern movie. So why do we see a scene that has been shot forty times from twenty angles (often in locations that aren't within a thousand miles of each other) as seamless?

A Bit of History

Before attempting to understand what makes editing work, it's important that we look at the past of the technique to gain some perspective on how it has evolved to its current state. "Throughout the history of the motion picture industry the quality of its products has steadily improved," (Walter, 19) and with this the art of editing has improved as well. In fact, the earliest films weren't edited at all.

When the Lumiere brothers invented the Cinematographe is 1895, the camera was a one-stop-shop. It not only captured the footage, but it allowed you to process it as well as project it all from within the same device. So as you might imagine, early filmmakers had little interest in cutting up the expensive film that they had purchased for use with their new toy. Instead, "the motion picture camera was loaded to capacity with film stock, and cranked away on the scene being played until the film in the camera ran out. At this point, the proceedings would be halted for the re-loading and then the film would continue as before." (Walter, 20)

Much of this arose from the traditions of which the movie industry was borne. Because people equated this new medium and its storytelling abilities with the theatre, it was never questioned that scenes should be completed in one take (or performance, in theatre terms). If an actor messed up their motions the whole reel was scrapped as if a thespian has flubbed his lines and needed to start over from the beginning. This led to a lot of wasted time, not to mention wasted film. "What the filmmaker saw is what the audience saw. It was a continuous unbroken piece of action, shot from a single camera angle, the perspective the all-encompassing, straight-on, eye-level view inherited from the theater." (Rosenblum, 35) The movies' other parent, photography, wasn't much help in progressing the medium toward editing either: the photographic tradition at that time called for stiff, rigid poses taken from a straight-on perspective.

Much of editing evolved through trial and error. People eventually figured out that they could make things more interesting (not to mention longer -- the first movies lasted only a few minutes at most because this is all that would fit on a single reel) by cutting up the film a bit and taping it back together. At first, however, this was only employed as a way of combining separate scenes: "If a picture was composed of more than one scene (a rarity), no attempt was made to link the last action of one scene with the first action of the next. Each transition was a total break." (Rosenblum, 35)

This was a big step forward for the evolution of editing but it wasn't until 1902 that Edwin S. Porter discovered that these scenes could be made to correlate to one another. With The Life of an American Fireman Porter realized that by placing scenes back to back they could be made to seem as though they were happening simultaneously. These were still whole scenes, though, that played from start to finish without a cut, and were then tied together by a larger narrative. In this short Porter also discovered that he could use footage recorded previously and in a different location as his main plotline and that the audience would understand that it was meant to take place at the same time. This was pretty fundamental stuff: that associations could be made between otherwise unrelated material, and really paved the way for the revelations brought about by D. W. Griffith.

Griffith is considered today and was even during his own day, a film genius; continuity cutting technique owes almost all of its origins to his discoveries. The first effective continuity cut was in Griffith's For Love of Gold, when a scene cuts "in the middle of the action to a full shot of one of the characters. No scene had ever been divided into more than one shot, and this simple innovation would soon cause a minor revolution." (Rosenblum, 38) Griffith soon found that he could create whole scenes composed of a series of different angles rather than just static ones and began playing with greater variations in distance. "Unlike the stage play with its constant flow of action and dialogue from the same viewing position, this deliberate breaking down of sequences into punctuated camera angles created a new dimension of pictorial interpretation." (Walter, 20) Griffith then began to realize that emotions could be elicited not only through the use of camera angles and literal content, but also through the pace of editing. All of this, however, was served in a way that had a heavy focus on making the cinema very real -- Griffith's goal was to create a cinema world that reflected our own.

This is in contrast to the work of Sergei Eisenstein. Eisenstein was a Soviet director who was raised on Griffith's films and learned much of his editing technique by watching faded prints of Griffith's Intolerance hundred and hundreds of times. By watching the films he was able to grasp not only how Griffith used editing to create drama, but he began to separate the various techniques and formed theories revolving around them. These various 'montage' theories (the word literally means 'editing') covered the various ways to edit a scene, or rather concepts around which a scene should be edited. For example, metric montage is based entirely on a steady pace of cuts, entirely independent of the content within the frame. Eisenstein considered this the most elementary of the theories. This is compared with rhythmic montage, which has a focus on pace but considers the elements within the frame, and tonal montage, which is cutting based on the similarity of the light and dark elements within the frame. Good examples of all of these from Eisenstein's film The Battleship Potemkin can be found here.

The highest form of montage, according to Eisenstein, was Intellectual Montage. This was a concept that Eisenstein created based on the idea that two images, when presented in juxtaposition, created a third and entirely new idea. "He illustrated his point with Oriental hieroglyphic writing, in which two symbols were joined to make an entirely new idea. Such was the case, for instance, when the symbols for eye and water were combined to yield 'crying.'" (Rosenblum, 48) The foundation for this idea comes from the so-called "Kuleshov Effect," named for Lev Kuleshov, who ran a school that Eisenstein attended. Kuleshov conducted a famous experiment in which he took footage of a soviet actor making a neutral face and cut it together with various other images. For example, the clip opened with the actor making a neutral face, cut to a baby crying, and then cut back to the famous actor. When audiences were asked about the actor's performance, they raved that he had shown such subtle emotion -- that you could see the feeling in his face. A separate audience was shown the same clip, only with the baby replaced by a bowl of soup, and the audience claimed that the actor was clearly hungry. (More on the Kuleshov Effect can be found here.)

The point of the experiment was to demonstrate that the juxtaposition of the two ideas could influence the meaning of both. Eisenstein took this idea and ran with it by saying that the third idea created by the juxtaposition (or in his language, "crashing") of the two images created a totally new third idea. A good example of this can be found in Eisenstein's October, in which Eisenstein juxtaposes Christian symbols with pagan idols in order to criticize the church. This idea of the combination of ideas is absolutely essential to film editing as we know it today, as more and more we see incredibly tight shots of characters that require our minds to link together and create a meaning between the various shots.

The Rules of Continuity Editing

Jump forward about a hundred years to present day. Given all the history between the creation of film editing and the present day, film editors have found a number of rules that allow them to maintain visual continuity and narrative clarity despite using an ever-increasing number of cuts. The ultimate goal of these rules is to make the actions in the scene remain clear and offer clues to the audience as to the spatial orientation of the scene. "Narrative clarity is achieved when a film does not confuse viewers. It requires matching action from shot to shot and maintaining a clear sense of direction between shots. It means providing a visual explanation if a new idea or a cutaway is introduced. To provide narrative clarity, visual cues are necessary, and here the editor's skill is the crucial factor." (Dancyger, 296) It should be made clear that there are a number of "rules" that editors use, and that these are just a few of the most basic and important ones for cutting within a scene. Many of these rules are not rules that must be followed by the editor so much as the production team, but that does not make them any less necessary to facilitate continuity editing.

#1: Maintaining Continuity Between Cuts
Finding continuity errors in movies is almost like a sport: there are entire websites online dedicated to noticing if there are any changes across edits in films. On a major motion picture set a specialist is employed solely to make sure that for every take objects remain in the same positions, actors deliver lines on the same beats, and even that an actor's hair falls in the same place. The reason this is so important is because editing is based on the idea that when we cut from one angle to another, the basic information between the two shots will remain constant and thus we will focus on what is happening rather than that the angle has changed. Because movies are often shot with just one camera at a time (in order to liberate the director to allow more possible camera angles) this further complicates the problem, as over the course of the several hours that it takes to shoot a single scene many things might normally change. Thus, keeping all factors constant is the first challenge of continuity editing. This includes light and color, as "variations in light and color from shot to shot can break continuity. These elements are under the cameraperson's control, but when variations do exist between shots, they can particularly problematic for the editor." (Dancyger, 303)

#2: The 180º Rule and The Line of Action
When the 3D space of our existence is captured onto film it is flattened into a 2D space and part of the challenge of working in film is to establish this 3D space on a 2D plane. When a scene is shot, an inherent left-to-right relationship is built automatically from the objects within the frame and it is important, if the goal is to make the editing transparent, that this relationship be kept in tact. In order to accomplish this "convention dictates that all subsequent camera positions should be restricted to the 180 degree arc established by the first shot. Avoiding crossing the line seems to give inexperienced film-makers their biggest problems, and it is extremely frustrating in the cutting room to be presented with shots which, although valid in themselves, cannot be intercut with the rest of the shot for that sequence." (Crittenden, 41) The camera can literally be placed anywhere on the side of the plane established by the master (or 'first') shot. Camera height does not matter -- it can be above or below the characters or even directly on top of them so long as their left to right relationship remains constant within the frame. See the figure to the right for a visual explanation of this concept.

This is important because we naturally expect the relationships of the things presented to us to remain constant. If the camera breaks the line of action (that is, the imaginary line that restricts the camera) and cuts to the other side of the line, it will appear as though the characters have switched places. Generally this is considered bad form, although it is admissible if the cut is so blatant that we can understand that the position of the characters has remained constant. For example, if two characters were standing against a nondescript black background and then we cut to an angle on the opposite side of the line of action against a similar black background, the audience would be confused as it appeared that the characters have swapped places. If, however, there are strong visual cues as to where the characters are, then a cut across the line of action becomes admissible, as our brain is able to place them within the space and understands that they were not meant to change places. Even when visual cues are weak we are often able to understand a cut across the line of action, but these cuts are jarring enough that they can take us out of the 'reality' of the film and remind us that we are, in fact, watching a movie. Many films use this to their advantage -- The Insider, for example, used it to symbolize a change in the balance of power in a conversation. It is important to mention, however, that actors are not bound by these limitations of cinema: it is very possible to establish a new line at any time during a scene. This can be done simply my either using a camera move that crosses the line to establish a new one or by characters moving to create a new orientation.

#3: Screen Direction
An extension of the 180º rule is the concept of screen direction. When a character is moving left to right in one shot, we expect them to continue to move left to right in the next shot because this is how we perceive day-to-day life. In fact, all action should be matched between shots in order to "be convincing and to allow the greatest flexibility in cutting." (Crittenden, 43) If a scene is shot with the 180º rule in mind and continuity is maintained then this should automatically happen when a character remains within the frame. But what happens when a character exits the frame? Because we understand that viewers expect screen direction to be maintained, if a character exits the right of the frame, we expect them to enter the left of the frame in the next shot. "This remains the case whether they are going across the screen, towards camera or away. If we ignore this rule it will appear that the person has changed direction on the cut." (Crittenden, 43) Just as with the 180º rule, though, this can be changed if a character changes direction while within the frame.

#4: Cutting on the Action
A huge rule in terms of cutting within a scene, cutting on the action allows editing to blend into the action occurring. "Suppose that a character is crossing the room in one shot and is seated in the next. These two shots do not match because we haven't seen the character sit down. If we saw her sit down in the first shot and then saw her seated in the second, the two shots would be continuous. The critical factor here is using shots that match the action from one shot to the next." (Dancyger, 296) It is the actual action within the shot that not only connects the two cuts but also distracts our eye from the fact that we are cutting to another angle. Because the screen direction has been maintained, our eye is able to track the motion continuously so we don't focus on the new surroundings but instead we follow the action. You can't, however, just cut on any action: "It is critical that the movement in a shot be distinct enough or important enough so that the cut can be unobtrusive. If the move is too subtle or faint, the cut can backfire. A cut is a promise of more information or more dramatic insight to come. If the second shot is not important, viewers realize that the editor and director have misled them." (Dancyger, 297)

#5. 30º Rule
Not to be confused with the 180º rule, the 30º rule dictates that when cutting between shots (especially of a single subject), the difference in angle between the two shots should be equal or greater than 30 degrees in order for the cut to be effective. A cut that combines shots that are too similar will be upsetting to the viewer. "What we do seem to have difficulty accepting are the kind of displacements that are neither subtle nor total... [such as if] the new shot... is different enough to signal that something has changed, but not different enough to make us re-evaluate its context. The displacement of the image is neither motion nor the change of context, and the collision of these two ideas produces a mental jarring -- a jump -- that is comparatively disturbing." (Murch, 6) This problem can often be solved via the use of a cutaway to a reaction shot or a close-up of something else and then returning to the second shot. This, however, is not considered strict continuity editing.

It should be noted that the list above is much closer to 'guidelines' than they are rules set in stone. Just as how poetry can break grammatical structure or even create new words, editing and filmmaking is not a formulaic process by which you just check off a list and have a completed film. Far from it: there are always situations in filmmaking which require breaking from the rules in order to convey the story. In fact, the story is only one thing that is more important than the editing -- Walter Murch offers a list of priorities to which an ideal cut should conform. "An ideal cut (for me) is one that satisfies all the following six criteria at once: 1) it is true to the emotion of the moment; 2) it advances the story; 3) it occurs at a moment that is rhythmically interesting and "right"; 4) it acknowledges what you might call 'eye-trace' -- the concern with the location and movement of the audience's focus of interest within the frame; 5) it respects 'planarity' -- the grammar of three dimensions transposed by photography to two (the question of stage-line, etc.); 6) and it respects the three-dimensional continuity of the actual space (where people are in the room and in relation to one another)." (Murch, 18) You will notice that the three-dimensional continuity is at the very bottom of his list. The demands of the story, pace, and emotion are much more important than a strict adherence to what literally happened on the set. In fact, this is one of the fundamental elements of editing: what shows up in the final product is hardly ever what 'actually' happened, and the art of 'cheating it' is one of the basic principles of filmmaking.

For a fun, visual explanation of these concepts, see this video.

So What? Why Does it Work!

Over the last 100 years filmmakers have created some very advanced rules from trial and error, but why do these work? Why is it that we can understand the jumps in space created by editing two clips together?

First and foremost, it is important to remember that film, as we see it in a theater, is 24 frames of information per second. But it is also 24 frames of black per second, thanks to the small space between the images on the film to which the image is captured. When we play this back, we don't see a series of alternating black and non-black frames, but instead we see continuous motion. This is thanks to the concept of Persistence of Vision, which manages to ignore the black in favor of following the simulated motion between the frames on the screen. In this sense, our mind is well-adapted to following motion despite an interruption in information.

But what about information across a true edit, something that was recorded at a different time and maybe even in a different location? Why is it that we can piece together these disparate images? "Nothing in our day-to-day experience seems to prepare us for such a thing. Instead, from the moment we get up in the morning until we close our eyes at night, the visual reality we perceive is a continuous stream of linked images." (Murch, 5-6) But this isn't quite true.

In an interview with the Christian Science Monitor in August of 1973, famous director John Huston found a keen insight into the basis of editing. "Look at that lamp across the room. Now look back at me. Look back at thtat lamp. Now look back at me again. Do you see what you did? You blinked. Those are cuts. After the first look, you know that there's no reason to pan continously from me to the lamp because you know what's in between. Your mind cut the scene. First you behold the lamp. Cut. Then you behold me." (Murch, 61) In this sense, our lives our cut every day into a series of short clips, each broken down into tiny pieces separated by the brief black of a moment's blink. We hold on to an image until we understand it and then we move on to absorb something else. The only exception to this is when we 'zone out.' It's surely happened to you: your eyes get fixated on something but you find that you're not actually thinking about anything. This is so unnatural, that your eyes would get caught somewhere without moving for so long without thought, that often people will attempt to break your line of sight and ask if you're ok. This is because our blinking is so strongly (and subliminally) associated with our line of thought: "I'm sure you've all been confronted by someone who was so angry that he didn't blink at all: this is a person, I believe, in the grip of a single thought that he holds (and that holds him), inhibiting the urge and need to blink. And then there is the opposite kind of anger that causes someone to blink every second or so: This time, the person is being assailed simultaneously by many conflicting emotions and thoughts, and is desperately (but unconsciously) using these blinks to try to separate these thoughts, sort things out, and regain some kind of controlÉ Even if there is no head movement, the blink is either something that helps an internal separation of thought to take place, or it is an involuntary reflex accompanying the mental separation that is taking place anyway." (Murch, 61-2)

Walter Murch expounds further: "I would go so far as to say that these juxtapositions are not accidental mental artifacts but part of the method we use to make sense of the world: We must render visual reality discontinous, otherwise perceived reality would resemble an almost incomprehensible string of letters without word separation or punctuation. When we sit in the dark theater, then we find edited film a surprisingly familiar experience." (Murch, 63) I believe that he is accurate in saying that we must break down the world, but I think he is overlooking the fact that we do this not only when we blink, but even more fundamentally with the saccades of our eyes. When we look around ourselves we do not make continuous motion with our eyes, but instead our eyes stick even if our head continues to move. Thus, the fact that movies are made up mostly of a series of static images that are related in context through light, color, and content makes sense to us. This is also why dolly and crane shots appear so "cinematic" to our eyes -- it is a perspective that we would never be able to reproduce with our human eyes because we are constantly focusing on objects and locking our viewpoint. It is only when we can fix our eyes steadily on a flattened screen that we can truly appreciate a smooth movement that is so foreign to our human experience.

So why does editing work? Essentially editing is built around the same concept as our vision is, that an experience should be broken down into multiple sections in order for us to better understand it. By maintaining elements constant on the shooting location, we imitate life as we experience it in real-time, such that there are no great changes from moment to moment. We also take in whole rooms and then begin to break them down piece by piece, just as in a change from a wide shot to a closer shot establishes the space and then moves in for detail. And by distracting the eye with movement by cutting on the action we are similarly mimicking the eye, in that the motion between two separate images (for the eye, the motion is subliminally recorded but mentally ignored between two saccades) helps us to combine the two of them. In essence, all of this is to say that editing works because it functions the same way that we do.

So the next time that you're in the theater, try to see if you can spot all of the rules and understand why the editing works. But don't forget to enjoy the movie!

Works Consulted / Cited

The Technique of the Film Cutting Room - Ernest Walter. Communication Arts Books. Hastings House Publications. New York, New York. 1973.

When the Shooting Stops: A Film Editor's Story - Ralph Rosenblum and Robert Karen. The Viking Press. New York. 1979.

In The Blink of an Eye: A Perspective on Film Editing - Walter Murch. Silman-James Press. Los Angeles.1995.

Film and Video Editing - Roger Crittenden. Blueprint. London. 1981.

The Technique of Film and Video Editing: Theory and Practice - Ken Dancyger. Focal Press, Boston. 1997.