Photography Perspective

Expressing Perspective: Techniques for Recording the Third Dimension

The portrayal of depth is often the primary attraction of a landscape photograph. To express the third dimension convincingly, you need to capture and arrange the features of a scene in a way that best projects their spatial qualities, keeping in mind that we see the world differently than does a camera. Not only do our two eyes work in stereoscopic view, but we move about, crane our necks and reappraise the scene from different angles to gain a better appreciation of depth and scale. By contrast, the still camera is afforded but a single, static view. To bridge this optical gap, we need to emphasize the cues in the landscape that express depth.

Size Cues: The relative size of landscape features is one of the most obvious cues in conveying the depth of a scene. Objects that are close appear larger than those that are far. Utilizing this cue is first a matter of incorporating familiar features in your composition that are similar in size, or at least are perceived to be so by the viewer, and then positioning the camera so that they are presented on film in differing proportions. Such components include trees, shrubs, wildflowers and animals of the same species. The ideal placement of the camera shows such size cues arranged at intervals on a diagonal plane or some variation of it (e.g., an S curve).

There are other less common but equally powerful size cues to which you should be sensitive. When cumulus clouds dapple the sky, they become smaller as they near the horizon. Sand ripples, caked mud flats and ocean waves can all be used to present a uniform pattern of decreasing size cues. From an appropriate camera angle, rivers, streams, sand dune ripples and fallen logs all exhibit the "railroad track" phenomenon -- the convergence of parallel lines toward a vanishing point (a variation on the size cue perspective effect).

Angles of View: Lens focal length generates a powerful perspective effect. By emphasizing the differences in size cues, wide-angle lenses increase the perceived distance between elements in the composition and promote a feeling of deep space. Telephoto lenses achieve the opposite effect by compressing the distance between elements in the scene. To accentuate these extreme effects you should position the camera as close as possible to the nearest size cue in the composition.

You normally will need to shoot at f/16, or smaller, to achieve satisfactory depth of field. Much of the time, you will be working in concert with other design prerogatives at some compromise distance.

Angling for Depth: Because the eyes of a standing human are some 5 or 6 feet (2 meters) above the ground, landscape features that are close to us are positioned lower in our field of view than those more distant (clouds excepted). For a maximum three-dimensional effect, you should set up at about a 45-degree angle (above the horizontal) on the first size cue in the composition. Use a focal length wide enough to include at least the horizon and a bit of sky. If you place the camera too low, you will lose visual exposure of the spaces between size cues; if you set up too high you will lose the horizon and the familiar eye-level configuration of the size cue. Either position results in a flattening of the scene.

You also need to position the camera horizontally so that the number of size cues portrayed is maximized and cues are kept separated and distinct. This step may require you to move the camera forward or backward as well as sideways. In most situations you should set depth of field to include both the closest size cue and features on the horizon (usually infinity). Setting camera position is normally a trial-and-error procedure exercised until the most effective design is achieved based on interrelated factors of color, light and subject matter as well as the desired perspective effect.