Elements of Cinematography

Cinematography
In cinematography, composition refers to the frame of the image and how the elements of the mis-en-scene appear in it. Composition guidelines must be observed when telling stories visually, as in filmmaking. Useful conventions are applied to make heroes stronger, villain ominous, generate anxiety, give the audience tranquility.

Lead Room

If a character is looking frame left, then he should be placed frame right. This makes the framing comfortable because the subject is looking at the open space in front of him. This open space is called lead room or lead space.If the actors were frame left, looking frame left, then the empty space would be behind them. This doesn't feel right because they would be looking at the edge of the frame. The proximity to the frame would generate a claustrophobic undertone that could upset some viewers.

Notice that when two shots of two actors in different sides of the screen are intercut together, the audience surmises that the actors are looking to one another, regardless of where they are.

Rule of Thirds

Another basic composition principle is called Rule of Thirds. To follow it, one must imagine the frame with two vertical lines and two horizontal lines, as to create three vertical sections of the same dimensions and three vertical sections also of the same size. The result is something like this:

The intersections of the lines are points of interest, where important objects are often placed. These points of interest are comfortable to the eye, thus the middle portion of the frame are kept "empty" or clear.

Filmmaker's Insight

Filmmakers, like any other group of artists, like to break rules. The guidelines here are just some basic concepts that any cinematographer or camera operator should know. In some circumstances, however, it's okay to stray away from these rules. 

Overlooking the norm is acceptable with motivation and purpose. With practice, you should be able to conceptualise extraordinary compositions and make them work in your favour. Consider Static Composition. Compositions with the majority of lines being horizontal or vertical are called Static Composition. In theory, horizontal and vertical lines are somewhat soothing, calm, tranquil.

REFERENCES
http://www.elementsofcinema.com/cinematography/composition.html