The rule of thirds is my favorite compositional too because it’s so easy to understand and use.
Simply put it’s a tool for creating dynamic and interesting compositions. The rule states that an image should be imagined as divided into nine equal parts by two equally-spaced horizontal lines and two equally-spaced vertical lines, and that important compositional elements should be placed along these lines or where they intersect. Aligning a subject with these points creates more tension, energy and interest in the composition than simply centering the subject would. I always say, Dead Center=Dead Boring!
The photograph to the above demonstrates the application of the rule of thirds. The horizon sits at the horizontal line dividing the lower third of the photo from the upper two-thirds. The tree sits at the intersection of two lines, sometimes called a power point or a crash point. I often call them Magic Spots! Points of interest (aka focal points) in the piece don’t have to actually touch one of these lines to take advantage of the rule of thirds. For example, the brightest part of the sky near the horizon where the sun recently set does not fall directly on one of the lines, but does fall near the intersection of two of the lines, close enough to take advantage of the rule.
A picture cropped without and with the rule of thirds:
There ARE other types of compositional tools, but they’re often difficult to understand by beginners. However, if you’ve mastered the rule of thirds, GO FOR IT and try out one of these!
The Golden Mean or the Golden Section
Here’s a powerpoint to help explain this beautiful, but very mathematical type of compositon: