One of the most famous photographs in history features a strong diagonal line and shows the importance of diagonal lines as a compositional device. The flag being raised by American troops over Iwo Jima would not have worked if the flag had been horizontal or vertical. The diagonal line implies action, movement and dynamism. I’m not for a second comparing my pictures to this classic, but below are those I shot as part of this exercise to explore this important design element.

All of the lines contained in the pictures above are actually horizontal (indeed the decking was also included in that exercise) or vertical. What makes them diagonal in these images is the perspective from which they are taken. Looking along these lines makes them diagonal. The combination of distance and lens choice exaggerates or reduces this effect. It is a very useful tool to communicate this distance to the viewer.

True diagonals, like those in this second set are less common, but they are around. As with most things, nature tends to do them best.

The eye moves across images containing diagonals more easily than verticals and particularly horizontals. Diagonals are used in composition for exactly that reason – to draw the eye in and to suggest movement and/or depth.
Having said that, I find it very difficult to ‘record’ the way my eye moves across an image at the moment. If I think about it, I’m sure I begin to control and so change its behaviour. That’s another subtlety of the discipline that I need to learn…

References.

Freeman, M (2007) The photographer’s eye – Composition for Better Digital Photos. Lewes; The Ilex Press

Forbes, T. (2012) Episode 114: The use of line in composition (Online). YouTube. Available from  http://compositionstudy.com/#/line/ [24 December 2013]

Raising the Flag on Iwo Jima (Online). Wikipedia. Available from  http://en.wikipedia.org/wiki/Raising_the_Flag_on_Iwo_Jima [24 December 2013]