Rule of thirds intersection of two of the lines, close enough to take advantage of the rule. 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. 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. Michael Ryan and Melissa Lenos, authors of the book "An Introduction to Film Analysis: Technique
Rule of thirds room should be in front of the subject with the vertical line running through their perceived center of mass. The rule of thirds was first written down by John Thomas Smith in 1797. In his book "Remarks on Rural Scenery," Smith quotes a 1783 work by Sir Joshua Reynolds, in which Reynolds discusses, in unquantified terms, the balance of dark and light in a painting. John Thomas Smith then continues with an expansion on the idea, naming it the "Rule of thirds": Two distinct, equal lights, should never appear in the same picture : One should be principal, and the