The Rule of Thirds
The rule of thirds in photography is a general rule, or guideline, that to create the most interesting, artistic, balanced, and dynamic composition, the image should be divided into nine equal parts, or thirds, both horizontally and vertically (think of a tic-tac-toe grid), and the subject of the photo—the most important or interesting part—should lie under one of the intersecting lines, such as in the photo of Mickey.
Mickey’s composition was achieved by cropping. I used rule of thirds when I was deciding how to crop the final shot.
20mm 2.8 lens @ 20mm, f/6.3, 1/320 second, ISO 160, aperture priority, spot metering
This might be easier to understand by visualizing the inverse of the rule of thirds: the subject is positioned smack-dab in the center of the frame (the center square or rectangle), which is usually, but not always, a less desirable look from the standpoint of artistic composition.
Willy’s composition isn’t very interesting because his face is in the center of the frame. If I had framed him so that his eyes were closer to the bottom ...