Crossing The Line: A Primer for New Filmmakers

New York City, 1989, NYU film school. I sat with 30 other aspiring filmmakers listening to Ben Hayeem talk about "crossing the line", an often undervalued and misunderstood piece of filmmaking grammar. 18 years have passed since that lecture and I still use the lessons he taught us that day.

To understand the "line", you have to first understand its importance in the right context: imagine you're verbally directing a blindfolded group of people through a rocky cave... except your instructions are on a pre-recorded tape. If you made one dictation mistake, your viewers might get lost, at least temporarily, and—because your instructions are pre-recorded—they're unable to clarify any misunderstandings... so everything you record for them has to be perfectly clear because any distractions would take their attention off the path. For example, if you gave them instructions in a thick foreign accent or used improper grammar, they might focus on that miscommunication rather than their path. Of course, there's no rule keeping you from talking with a thick foreign accent or using grammatically questionable words like irregardless, but making those kinds of missteps risks distracting, confusing, or even alienating, your viewer. Seriously, why risk it?

The "line" is a filmmaking convention used to help viewers immediately grasp where their viewpoint is in relation to the action of a scene. It originates from the confines of a stage play and, like many artistic techniques, is only noticed when not executed skillfully. The line is usually associated with a character's sagittal plane (see above diagram)—an imaginary line slicing right down the middle of our bodies—because the sagittal plane follows human interaction the closest: we usually face each other when talking and each actor's sagittal plane can be joined into a rough line that establishes the domain of an imaginary stage.

Before I explain the line in detail, here's a visual example. Imagine you see these two guys, Jet Li and Donnie Yen, from Hero:

You can safely assume that they're looking at each other, right? Jet Li is on your left and Donnie Yen is on your right. Got it?

But then the next shot you see is this:


Something's wrong: Jet Li was supposed to be on the left, yet he isn't... I'm so confused. Instead of enjoying the scene, I'm distracted by trying to re-orient myself... oh wait, I get it—we're not seeing them from the same side! The camera has jumped across the imaginary lines connecting these characters' sagittal planes. That's crossing the line.

Here's another filmic faux pas:



Though these guys are really looking at each other, they appear not to because the camera has crossed the line for one of the actors, but not both. If these two shots were the only ones we saw, we'd be very confused if the actors started fighting each other because it looks like they're actually facing the same direction.

So okay, you're getting a feel for this. Time to really break it down.

Let's assume I'm sitting at the back of a room, and in the middle of the room are two people: Person A on the left wall and Person B on the right wall. If these people talk to each other, there's an imaginary "line" you can draw between them and when I look at them, my head snaps back and forth as if I'm watching a Tennis match.

Person A (on my left) looks to my right, or "camera right", while Person B (on my right) looks to my left, or "camera left". Simple, right?


A —> <—B


The assumption is that I haven't moved. But let's say I walk to the front end of the room, excusing myself as I pass directly between both guys. When I turn back to look at them, I see this:


B —> <—A

Here's what all that looks like on paper (the camera angles are color coded):


When you walk from the back of the room to the front, you cross the line, which isn't bad in itself... just that changing the camera angle on one actor by crossing the line suggests that the other actor's camera angle should change in tandem. Otherwise, the viewer can get confused about where their point of view has been suddenly moved to. As in everyday speech, we could use a double negative ("I don't see nothing") and still convey the grammatically correct meaning ("I don't see anything"), but a double negative is distracting to many people. So why use it?

Here is the entire sequence from Hero in its exact order, with commentary:


Master, Jet (L) & Donnie (R). Establishes the geography of the scene.


Med, Donnie. "You don't scare me!"


Med, Jet Li. "But I'm Jet Li."


Med, Donnie. "Hmmm, perhaps you are a worthy opponent." No problems so far; we're watching a tennis match.


Beginning of Med Dolly shot, Jet Li. Okay, we're crossing the line here... Jet Li went from looking camera right to camera left.


End of Dolly shot, Jet Li. ...as long as the next shot of Danny isn't looking camera left as well, everything will be cool.


Med, Donnie. Doh! Since Donnie is also looking camera left, now the viewer might be confused. But now we're dollying...


... and we're moving to cross the line now...


Jet is ever ready. His eye line is now almost perpendicular to the camera.


Finally, we've crossed the line for Donnie.


Jet.


Donnie.


Okay, we've successfully moved across the line. Almost. The viewer got a clue that the camera was moving across the line, and while the shots weren't perfectly in sync, the camera stays on the other side of the duo.


What's this? Oh, the music guy. He's putting away his musical instrument.


Now he's walking away.


Okay we're back to Jet & Donnie... but WTF??? Are we back to the first place we were standing??? Hmmm. Well, okay. I guess the camera will stay here for a while.


In the next shot, a dream sequence, the camera has jumped back over the line again! Aaaaaaaaa!!!!


Ideally, as a director, you should never be worrying about the line—that's what your script supervisor is for. In theory, they'll be constantly double-checking the Cinematographer's setups to see if he's crossed the line. In reality, I once had an experienced editor on set to verify the complex staging checked by the script super, DP, and the director... and all of us still got it wrong. Without storyboards, it's dangerously easy to cross the line.

Fortunately, most people don't even notice when directors cross the line because a good establishing shot will tell the audience where the actors are within the scene. In the example above, with only two actors and wide establishing shots, it's safe to move the camera over the line multiple times with no noticable effect. However, without that wide establishing shot to orient the viewer, or if the scene involves a ton of characters, planning out shots to avoid crossing the line can mean the difference between being an amateur and looking like a pro.

Here's the entire clip from Hero:



In researching this article, I learned that Ben Hayeem died in 2004. He was a soft-spoken soul who taught countless filmmakers the nuts and bolts of the craft. We keep Ben's lessons at heart as he lives on through us.