The rule of thirds is a guideline which applies to the process of composing films and photographs.
The main reason for observing the rule of thirds is to discourage placement of the subject at the center, or prevent a horizon from appearing to divide the picture in half.
An image should be imagined as divided into nine equal parts by two equally spaced horizontal lines and two equally spaced vertical lines.
Important compositional elements should be placed along these lines or their intersections. Aligning a subject with these points creates more tension, energy and interest in the composition than simply centering the subject.
The Rule of Thirds is Applied by:
- Aligning a subject with the guide lines and their intersection points
- Placing the horizon on the top or bottom line, or
- Allowing linear features in the image to flow from section to section.
Learn more about the Rule of Thirds in this video tutorial