The Rule of Thirds

When we look at a film or photograph, there are a number of subconscious things our minds look for and either enjoy or don't enjoy. There are certain areas where we can place objects of interest to make them pop out to the average eye. This is called The Rule of Thirds.

 Basically, you split the LCD  or viewfinder of your camera into nine equal parts, like in this image taken from http://digital-photography-school.com/rule-of-thirds:

Why do we do this? It has been tested that the mind will look at any one of the intersections of these points more so than the center of the shot. What is the first thing you looked at when you looked at this picture? Personally, I was drawn to the eye of the bee, which is right on one of the intersections. So, by placing subjects of interests along the lines or on/close to the intersections, you draw more attention to them.

 This translates to cinematography by allowing the cinematographer to make objects of interest pop out compared to the rest of the shot. For example, if you were doing a horror scene wherein the antagonist is stalking the protagonist, a facial shadow of the antagonist in the window placed on the upper right intersection as the protagonist walks away towards the camera in the center would draw attention to the shadow and would increase the feeling of suspense.