Compositional element: Horizonal lines, vertical lines, weak diagonals. Lituya Bay, AK
Photographers should regularly remind themselves that pictures aren't reality, but are static, two-dimensional representations. Whether it’s on paper or your monitor, a picture is a frozen world. To thaw the freeze, show action, or re-create movement, look to the diagonal line, among the strongest of compositional elements. Diagonals imply action. Take a tree as an example. The tall , vertical trunk of a living tree may be impressive - it’s loaded with "potential" energy - but it’s not particularly dynamic. Similarly, think of a dead, fallen tree lying horizontally on the ground. It's at rest, passive, its energy spent. Now think of a trunk on, say, a 45º angle. Unless it’s supported, it’s not just moving, it’s crashing. We understand this intuitively, so when we see a diagonal line in a picture, we ‘feel’ the action.
Compositional element: Strong diagonal line, Lituya Bay, AK
In the composition on the left, the kayak forms a horizontal line, and is aided by vertical elements formed by the cliff. A few weak diagonals — from cliff, shore and parallel paddles — save the composition from being completely mondane. I've submitted this photo for publication, but its never sold.
The photo on the right, in contrast, has a strong diagonal — formed by the bleached tree — that directs you straight into the scene and adds a dynamism that the first photo lacks. Photo buyers like it. It's been sold as a magazine cover and a contents page, and is likely to sell again and again.