How to Use the Rule (or Suggestion) of Thirds in Photos Bryan Peterson, photographer and author, doesn't like to stifle creativity. So in his new book, "Understanding Composition," when he describes the rule of thirds, a classic composition strategy, he prefers to call it the suggestion of thirds. There are a lot of theories on why the rule of thirds works, none of them definitive. But there is general agreement that it does improve many photos. To use the rule of thirds in a basic way, imagine a tick-tack-toe board over the scene you are framing for a shot; some cameras and phone camera apps let you place an actual grid in the viewfinder. Put the subject of your picture where the lines cross, which is a third of the way from the top or bottom and left or right. It seems simple, but there are decisions to be made about what the subject should be and how to place it. Mr. Peterson explained using photos from his book. "The argument for this composition is, the focus point was dead center, so you made the main point where the focus was," Mr. Peterson said. This kind of photo is good for documentation, but it lacks artistry. "To me it's an incredibly static image," he said. Static is photo lingo for boring. Moving the tree a third to the right is an improvement but not a large one, because the horizon is still centered. Here is where another decision is made: "Is interest greatest below the horizon line, or above the horizon line?" Increasing the amount of sky is an improvement - the photo now conforms to the rule of thirds - but Mr. Peterson isn't finished. The sky, he said, is "what I refer to as 'vanilla blue.' There are no white clouds, it's empty. So if the question is which is more interesting visually, the sky or the field, the cloudless blue sky loses. With the tree off center, and the flowers filling the foreground, "we have introduced some degree of tension," which is photo-speak for interest, Mr. Peterson said. The rule of thirds works for many compositions, including portraits. The trick, Mr. Peterson said, is to get close and fill the frame: "You're not close enough until you have cut off part of the person's forehead. In my opinion, that is when you are close enough for a really intimate portrait. With that done, most photographers will naturally apply the rule of thirds. There is one technical trick to using the rule of thirds. Most cameras will automatically focus on the center of a frame, even if that isn't the intended subject. There are a number of ways to shift the focus to the subject. The most obvious is to turn off the automatic setting and focus manually. There is an easier trick that works for most cameras, which is to push the shutter button halfway to hold the focus. All you have to do is to put your subject in the center of the frame, and press the shutter button halfway. All of the settings will be locked. Now, still holding the button, frame the shot the way you want, and then press the button fully. Your intended subject should still be in focus. Finally, many digital single-lens reflex cameras have movable focus points, meaning the camera can be focused automatically on a point that is not in the center. Most cameras have at least three focus points; some have more than 60. Check the manual to see how to do it. Although the rule of thirds can help many photos, even abstracts, there is a reason that Mr. Peterson calls it a suggestion. "Some things do look better then they are smack dab in the middle," he said.