1. The 3D Composition
The film or video camera captures a flat, two-dimensional image and the movie theatre, television, and computer screens display a flat, two-dimensional image. So how is it that when we watch television and, more noticeably, movies on very large theatre screens that the elements of the frame (either static or moving) seem to occupy a three-dimensional space? Well, the simple answer is to say that this phenomenon is achieved through visual illusions and tricks for the human eye and brain. There are many more in-depth physiological and psychological reasons, but this is not the appropriate place to explore those topics fully. Feel free to do your own research on the human visual system and how we interpret light, colour, motion, depth, and so forth.
What we can discuss briefly is how our human visual system differs from the visual system of a film or video camera. On the most simplistic level, it comes down to how many lenses get used to creating the image. Humans have two eyes on the front of their heads, and the eyes are spaced several inches apart from one another. This configuration results in binocular vision. Binocular vision allows us to establish depth in our visual space by causing us to see the same objects from two separate vantage points. Each eye sees the same objects from slightly different horizontal positions and therefore “ captures ” a slightly different.
Picture — offset by those several inches of distance between the two eyes in the head. The brain then unites those two separate pictures and generates one view of the world
around us rendered with the three-dimensional perspective. Most fi lm and video cameras, of course, only have one eye — the single taking lens — so they are unable to record the same type of three-dimensional space as the human eye. Therefore, fi lmmakers must generate the illusion of multidimensionality. The illusion of depth on the 2D plane of fi lm or video can be created in many ways. For now, let us explore how to be great 3D illusionists with our shots.
2. Horizon Line
We are going to leave our human subjects aside for the time being and put our attention into shooting a generic exterior. Shot-wise we are talking about the long shot family, especially the extreme long shot (XLS). Depending on the surrounding topography of your shoot location and your camera angle, this shot should result in capturing a large field of view of the world — the ground, the sky, and many things within those zones. For illustrative purposes, we will keep the environment rather bare and start with just a horizon line.
The horizon line is what keeps a viewer locked in a knowable spatial relationship with the film space. In other words, it keeps them grounded by allowing for a clear up/down and left/right orientation. Your major goal should be to keep your horizon line as level as possible and in alignment with — parallel to — the top and bottom edges of your physical film or video frame. This is relatively easy to do by eye when you are shooting an Earth-bound project, but what happens when you begin to shoot in outer space? Where is the horizon established then? That is something for you to ponder on your own. For now, we will stick to the surface of the Earth and keep things level. You will see that the aforementioned illustration accomplishes this goal, but let us add actual objects to help further discuss horizon line and composition.
Now we can begin to appreciate what the level horizon line is doing for our picture composition. The horizon bisects the frame separating top from bottom. There is headroom for the mountains, sun, and clouds, but does the image follow the rule of thirds? Does it have to? Horizon lines may be placed across your frame wherever you see fit, but its placement will allow you to highlight more sky and less ground or less sky and more ground. If we tilt the camera angle down, we push the horizon line up in our frame. If we tilt the camera angle up, we push the horizon line down in our frame. Each of these examples shows the horizon line following the rule of thirds. To many, this is a more pleasing position within the frame.
3. Dutch Angle
You will most often strive to keep your horizon line stable and level, thus ensuring an even viewing plane for your audience. A shift in your horizon line is also likely to cause shifts in your vertical lines — any tall building, tree, door frame, and so on will look tilted or slanted, not upright and even. When horizontal and vertical lines go askew it causes a sense of uneasiness and a slight disorientation in your audience. If this is done unintentionally, then you get people confused. Done on purpose and you have created what is called a Dutch angle, a Dutch tilt, a canted angle, or an oblique angle. When a character is sick or drugged or when a situation is “ not quite right ” you may choose to tilt the camera left or right and create this nonlevel horizon. The imbalance will make the viewer feel how unstable the character or environment really is — visuals underscore the story
4. Diagonal Lines
So far, all of these horizon line examples have been locked in two-dimensional frames. The strong horizontal line, one-third down the screen from the top, is a good compositional start, but it does not create depth. You need to establish that this XLS captures depth in the physical world of the fi lmed image. To help with this goal, you could employ an old artist’s trick called the vanishing point . In our current example, we could have placed our camera in the center of a two-lane highway that stretches straight out to the horizon. For the most part, roads have a consistent width and therefore the lines that represent the edges of the roadway should be parallel to one another for as long as the road covers the ground. When observed across a large distance, however, the edge lines seem to get closer and closer together until they appear to merge at the horizon. This place along the horizon where parallel lines appear to merge together is the vanishing point.
This simple illustration represents the receding roadway with two diagonal lines. Again, in reality, the road’s width should be constant, but as we observe in reality, in drawings, and on a filmed image, when viewed over a long distance, the lines of the road appear to converge. This is, of course, an illusion. The key thing to realize here is that the diagonal lines bring that illusion of depth to our frame. So, whenever you can employ diagonal lines within your composition (a road, a hallway, a line of people waiting for the bus) you are creating the impression of three-dimensional space on the two-dimensional fi lm frame.
This does not mean that you must always use diagonal lines, however. Yes, they are compositionally bold elements within your frame and yes they can create depth, but what if your goal is to create a shot that has no depth? You want your character to appear in a flat space, like up against a wall — reflecting the story’s subtext and psychological meaning — she is trapped or she is not capable of moving in a dynamic direction at this point of the narrative. To achieve the shot, the camera had to be placed at the height of the actor and perpendicular to the wall itself. This frame, flat on to a wall, has no real sense of depth. The full-frontal angle on the action only shows some horizontal lines on the wall. The person is enclosed by the environment and can only move left or right, or potentially toward the camera. In this instance, the absence of perceived depth adds to the mental or emotional state of the character. The composition of the shot underscores the state of being for the character recorded within it.
A slight shift in the camera’s angle on action (horizontal repositioning) yields a different image with a different meaning. It shows the same woman in front of the same wall, but now a diagonal line exists, as does a distant horizon. With the frame opened up this way, the character has more options for movement — left, right, near, or far. Depth is created because we can now see out into the world along those diagonal lines that draw the viewer’s eye away from the main character and out into the deep space
of the film world — an illusion of the third dimension is created on the flat film frame
