This image is made distinctive because of its linear perspective. By being above the thousands of Jayhawk fans and framing down several blocks of Massachusetts Street, the viewer has the illusion of depth and scale even on the two-dimensional surface of a photograph. Both the dark shapes of the buildings and the bright street lights lead the eye to a point of convergence down the street and over the crowd gathered to celebrate Kansas University’s men’s basketball championship April 7, 2008. This photo was taken from the roof of the Eldridge Hotel looking south.

In my continuing series on visual devices for photography, we’ll look at linear perspective this week. Unless using specialized equipment, a camera is only capable of capturing two-dimensional representations of three-dimensional objects. So in efforts to add the impression of depth and scale to an image, I often rely on the technique of linear perspective.

Linear perspective is the impression of depth given by converging parallel lines and changes of subject scale between foreground and background elements.

I use this technique in my daily work, where I can find the various attributes of linear perspective: objects getting smaller the farther away they are from me, or lines receding into the distance. Then, I exploit these elements to add more depth into the image.

This past March, I was photographing sandhill cranes feeding in a cornfield in Nebraska. At ground level the crane appeared flat and lacking scale against the sky and horizon. By standing up on a small rise and reframing the crane in the field, I added a sense of depth to the image using the converging parallel lines of rows of corn stalk remains.

This feeling of depth is only an illusion, but it is an important compositional factor. It can be as simple as framing a straight stretch of highway converging at a distant horizon or photographing a row of houses from an angle so each house appears increasingly smaller to a distant point of convergence.

Another tip to consider: A wide-angle lens will cause the linear perspective to be overemphasized, while a long telephoto will reduce the sense of distance.

Knowledge of the way different perspectives work can help improve the composition of a photograph.