Last summer, I visited my home state of Louisiana for a photo shoot of my great-niece. Prior to this trip, the majority of my professional work had been done without models and was mostly landscape, nature, and wildlife work.
Arranging the subjects and objects in a photograph and establishing their respective places in the scene is known as "composition". Much composing is done, and can only be done, through the viewfinder prior to releasing the shutter. Some alterations and improvements can be done with digital editing after the image is out of the camera and into the computer. Some image editing software actually superimposes this grid on the image to help. Some cameras have the grid visible in the viewfinder. A few years ago, I attended a weekend workshop put on by the Rocky Mountain School of Photography. I had been familiar with the “rule of thirds” for a long time and for some reason always applied it horizontally. At this meeting, they pointed out that if you apply the same rule vertically; the two groups of lines form a “tic-tac-toe” grid with a square centered in the frame.
The four corners of this square are the “power points,” the four areas of the photo where the eye naturally tends to look in a scene.
The upper left hand power point is the most significant. Regardless of culture and reading path (up, down, left to right, or right to left) the human brain goes to that spot first. (There is actually scientific evidence to support this comment although I do not have the reference to link.) The eye is naturally attracted to the brightest, most clearly focused feature of a scene.
Triangles are the most powerful of geometric shapes in a composition because they help to keep the viewer’s eye in the frame and they help focus attention on a particular point in the frame.
Three is the preferred frequency for number of items in a scene, i.e., three flowers arranged in a triangle. Notice in this first illustration the grid lines as well as the two triangles. Also, note the gradual change in brightness of the triangle's three sides, ending with a smaller solid white triangle in the upper left power point. Or rather, try NOT to notice them. See how powerful these elements are to the composition?
These rules work for any subject matter whether it’s a landscape or a portrait. For a portrait, we try to get the eyes on the upper third line, hopefully near the two upper power points.
Photo number one (click to enlarge) is a simple head shot and as you can see, the composition grid lines match up well with the Chelsea's features.
In the next photo, the model reclines and we see the main power point dead center on her face. Finally, a full-length shot that employs the use of triangles to keep the viewer's eye in the frame and, at the same time, ensure attention to her face.
It is important to keep these composition tips in mind while framing the shot in the viewfinder. As mentioned above, it's possible to make minor corrections with a cropping tool in post production if you have an image that isn't beyond repair.