Dimensional Space

This article follows on from my earlier post about diagonals and their role in composition. My own path towards becoming a better photographer has always involved learning how composition works. Lines are important, but they are only part of the story. We also need to understand how a photograph creates a sense of space.

Space is a place

We are always in some kind of space, but we rarely stop to think about it. A place might feel inviting, bright and open. It might be bleak, dark, mysterious or overwhelming. It can be expansive, or cramped and crowded. Each of these qualities influences the way a photograph feels.

We live in a three-dimensional world, but a photograph is a two-dimensional surface. The challenge is to suggest depth and physical presence within that flat frame. When we succeed, the viewer can almost imagine stepping into the scene.

There are several visual cues that help create this implied space.

Creating the illusion of space

• Relative size and position: Larger objects often appear closer than smaller objects of a similar kind. Placing recognisable objects at different distances gives the viewer clues about depth. A row of similar objects can be particularly effective because the changing scale suggests how far the scene extends.

• Occlusion: Overlapping objects are among the clearest indicators of depth. When one object hides part of another, we understand that they occupy different positions in space. The shapes need to be recognisable for this cue to work.

• Colour and atmospheric effects: Warm colours can appear to advance and cooler colours to recede, although this is not an absolute rule. Atmospheric perspective is often more convincing: distant objects lose contrast and saturation as particles and moisture in the air scatter light.
• Texture and shadows: Texture gives the viewer clues about the surface of an object. Cast shadows help explain the relationship between objects and the surfaces around them. Their direction, softness and position can all contribute to the impression of depth. Reflections can provide similar spatial information.

Perspective systems

Perspective is another powerful way to suggest depth. In photography, the most familiar forms are linear perspective and atmospheric perspective. Overlapping shapes and relative scale contribute too.

One-point perspective

In one-point linear perspective, parallel lines appear to converge towards a single vanishing point, usually on the horizon. In the photograph below, the poles lead the eye towards the same point. Their decreasing apparent size strengthens the impression of depth.

Gary Plummer, “Pier”.

Two-point perspective

In two-point perspective, two sets of parallel lines appear to converge towards two vanishing points on the horizon. A building photographed from a corner is a familiar example: the two visible sides recede in different directions.

Parallel and isometric-looking compositions

Some compositions retain parallel lines rather than showing them converging towards a vanishing point. This can create a flatter, more diagrammatic impression, particularly in architectural and panoramic photographs. Strict isometric projection is a technical drawing method, rather than a normal photographic perspective, but the visual effect can still be interesting.

Atmospheric perspective

Atmospheric, or aerial, perspective describes the way distant objects appear less distinct because of the atmosphere between the camera and the subject. Imagine standing in front of a field. A nearby tree has clearly defined edges and strong colour. Further away, the trees become smaller in the frame, less distinct and more muted as haze reduces contrast.

Gary Plummer, “Foggy Morning”.

Mountain ranges are another beautiful example. Each ridge recedes into the distance, becoming lighter, less saturated and less sharply defined. The changing layers give the photograph a convincing sense of scale.