Composition Rules

 Composition is the placement or arrangement of visual elements or ingredients in a work of art, as distinct from the subject of a work. It can also be thought of as the organization of the elements of art according to the principles of art. This article will cover the mostly used terms in general manner so this applies on photography and 3d rendering both.
The Rule of Thirds

There are times when you need to place your subject in the centre of the frame, you can create more interesting, balanced and powerful compositions by placing the subject off-centre in your photograph. A technique that can help you visualize your shots is the rule of thirds. The rule of thirds means to view your shot through a grid made up of three equal parts, both vertically and horizontally.
This immediately cause the viewer’s eye to move around the image – centrally placed subjects tend to focus attention in the middle of the image and leave it there, making pictures feel flat as a result. If you’re trying to create an abstract or graphic representation of reality, this might be exactly the technique you’re looking for. This rule is a basic principal often used in photography, video and film.
One of the most frequently used ways of directing the viewer’s eye to the centre of interest in a picture is by following the rule of thirds. Infact, there are lenses you can buy for cameras that makes this rule visible through viewfinder and allows you to visualize where to place your characters and subjects.
Visualizing your shots in thirds is like adding graph paper over your camera lens, allowing you to align and balance subjects. In order to know if you are using the rule of thirds properly, think of sight lines or readings. When you are presented with a new image, for example, the eye goes to the most prominent shape in the frame, which is called the first read. Then the eye wanders to a secondary shape, the second read, and so on. Keep practicing it, and the rule of thirds will start to work itself into each of your shots.
Depth of Field

One complaint in many 3D animations is that they look “too clean”. So, what do you do? You can add more detailed textures, better lighting, softer shadows, and even radiosity. But watch any movie, and you’ll see something not often put into 3d animations: depth of field.
When a lens focuses on a subject at a distance, all subjects at that distance are sharply focused. Subjects that are not at the same distance are out of focus and theoretically are not sharp. However, since human eyes cannot distinguish very small degree of unsharpness, some subjects that are in front of and behind the sharply focused subjects can still appear sharp. The zone of acceptable sharpness is referred to as the depth of field. Depth of field, often called DOF in animation software.
You can use depth of field in a number of shots:
1) Over the shoulder shots
2) Close-up shots
3) Product Shots
4) Landscape Shots
5) Crowd Shots
Depth of field can also be animated. For example, many shots in movies and television use rack-focus shots. These are shots that changes focus over time, perhaps from one person talking to another. The cinematographer needs to manually adjust the focus, aperture and other settings on the fly while shooting the scene. In the digital world, it’s much easier. You can assign a focus point to your 3d camera, set an appropriate f-stop, and then simply keyframe that focus point at any desired time.
So, add more depth in your image or animations through Depth of Field.

If you have experience in film and photography, you should certainly know about aperture. Simply put, the aperture is an opening, generally a circular hole or similar shape, within a camera lens that control the amount of light coming into camera and onto the film or computer chip. The aperture is controlled by f-stops. The “f” refers to the focal length of the lens divided by the aperture.
f/stops are a bit more confusing because the numbers appear so arbitrary. This is the standard sequence of f/stops from f/1.4 to f/22. Although it doesn’t seem intuitive at first, in this sequence the f/1.4 setting lets in the most light while the f/22 setting lets in the least. Also, each of these f/stops has precisely the same halving/doubling relationship as the shutter speed sequence.
1.4 2.0 2.8 4 5.6 8 11 16 22
On the face of it, going from f/4 to f/5.6 doesn’t sound like halving the amount of light. What’s more, 5.6 is a larger number and sounds like it ought to be more light, not less. Neither does f/4 to f/2.8 sound like doubling the amount of light.
# Low f-stop, more light (larger lens opening)
# High f-stop, less light (smaller lens opening)
So when do you allow more or less light into the camera and why? And how does the f-stop play a role? A basic understanding of photographic principles can help you assess your 3d situation in terms of both lighting and depth of field. You should understand it and use it.