One of the aspects of great photographs is the illusion of depth; the sensation of looking into an image when, in fact, all we're really looking at is a flat surface. Depth helps a photograph become three-dimensional; the scene becomes a gateway into another world. Viewers feel as if they can step into a picture and take a stroll amongst its elements.
In art and photography we use flat surfaces to communicate ideas and depth helps us to bring an emphasis to the subject matter of the photograph. With some effective techniques and the use of elements of design the flat surface can easily be transformed into a three-dimensional space. Below, six techniques are listed that you can use to achieve just that.
1. Light and shadow
Light and shadow help us to make sense of what we see and to understand texture, dimension and perspective. Perhaps the most important part of working with lighting is knowing where the light is coming from. The best light for defining depth is side light, especially when the light is low relative to the subject, such as in the late afternoon or early morning. Shadows are long, helping to place the object in its environment and adding visual depth and texture to the image.
2. Linear perspective
Linear perspective is characterised by converging lines. Scenes of roads, railroad tracks, tree lines and fences employ converging lines to lead the eye to a distant spot and enhance the feeling of space. The choice of a lens will hugely influence linear perspective. A wide angle lens enhances it. A telephoto lens, on the other hand, reduces linear perspective, especially when used from a distance.
3. Diagonal lines
Just as depth is perceived by the narrowing of a road into the distance, you can use diagonal and curved lines to make your pictures more three-dimensional. These lines take the viewer on a "journey" through the image and also create a sense of drama in a scene. In abstract photography diagonal lines are employed to enhance depth due to the interesting geometric shapes that they create.
4. Overlapping objects
When there are no obvious receding lines, we can pick up clues about space in an image in other ways. For example, the overlapping of objects is another way of creating depth. When one object covers part of another, the first object looks closer. If these overlaps are repeated within the image, they give the viewer a sense of depth and a perception of the relative distance of the objects.
The temperature of colour and its brightness also create a sense of depth in the image. As humans we tend to perceive bright, warm colours like red, orange and yellow as being close, and dark, cool colours like blue and dark purple as being further away. This is particularly true for abstract art. If you are working in black and white you can use contrast to produce an illusion of three-dimensional space. Visually high contrast makes things loook closer while low contrast makes things look further away.
The sharpness of the object, especially in the foreground, will enhance the impression of depth. In general, objects that have more intense colour, detail and contrast often appear closer than objects that are more blurry, more hazy and have less focus.
Not all images require a sense of depth to be more dramatic or more realistic. But whenever the perception of distance is important, knowing which technique is available and how to use it is a very useful tool worth exploration.