The Rule of Thirds is based on the idea that the human eye is naturally drawn to a point that follows the suggestion of the golden mean. Superimpose a tic-tac-toe grid on most aspect ratios and you might be surprised how many compositions follow this basic influence on photographic composition, visual design. See where the strongest and most contrasting points fall on the intersecting lines of that grid, creating movement through the frame.
At the Dam Cafe at Hoover Dam are these umbrellas, stainless steel structures that provide shade for the Dam tourists. The intricacies of the umbrella structure and morays induced by the patterns of the holes in the canopy inspired this shot.
If the area of interest is land or water, the horizon line will usually be two-thirds up from the bottom. Alternately, if the sky is the area of emphasis, the horizon line may be one-third up from the bottom, leaving the sky to take up the top two-thirds of the picture.
Faces lend themselves to the golden rule, unique compositions in and of themselves, but frame them under the same compositional influences using thirds and the images breathe. Imagine if each of these were framed dead-center, static.
Daniel and Lindsey flirt a bit with the frame that is closest their faces. For Daniel it's camera-right and Lindsey camera-left. Thirds force them to the frame which induces a bit of bounce back with their eyes, taking your eyes into the frame, for Daniel from left to fight and for Lindsey just the opposite.
Amber's composition exploits the thirds rule as well, but the energy here is more riveting on her eyes by the placement and the lack of influence of the frame. There is no ricochet like the two above, so framed due to a number of factors; the sub-composition of the contrast of her hair against her hoodie against the background, and the remarkable agreement between her eyes and her smile.
I don't recognize these influences during the shoot. It's more a matter of trusting the movement of my own eye in the viewfinder and the subtle adjustment of the film plane to capture something that communicates.
The Diagonal Rule
This establish of the Dam Cafe sends the eye on a z axis through the frame via the strong vertical lines of the railing.
Vectors
Indications of direction are considered to be vectors and can be categorized into graphic, motion, and index vectors.
Graphic vectors have a strong sense of direction such as strong architectural angles of a building or lines painted on a roadway surface. These vectors encourage eye movement through the frame along the vector line.
The diagonal graphic lines etched in the walls of this slot canyon force the z-axis attraction.
The motion vector of the car above points to space for it to move into, giving it a psychological sense of balance, space and momentum.
The motion vector of this here leads the car right into the frame creating a sense of trapping or nowhere to go.
