Shadow is a color as light is, but less brilliant; light and shadow are only the relation of two tones.
In a world of shadows and highlights, the highlights seem to get the most attention. We watch highlight reels on TV, mark our documents with highlighters, and describe positive events as the highlights of our days. When it comes to photography, most of us are probably more attuned to highlights than to shadows, if for no other reason than because they are the brightest and most readily noticed parts of an image.
But let’s talk about those underappreciated shadows. Shadows are in many ways the backbone of a photograph. They provide depth and dimension, while adding critical details, contributing to overall contrast, and supporting the flow of light across the scene. These functions are especially important in architectural photography, where we are usually trying to make things look as three-dimensional as possible, while capturing a full range of details in order to elucidate a design. Attentive handling of shadows can elevate a photograph, while ignoring them can make the image fall short.
One of the most useful ways to think about shadows is in terms of detail. In general, it should be a goal in any photograph to preserve some amount of detail in the darkest parts of the image. Let’s see why.
In this photo, the area under the stairs is considerably darker than the rest of the scene. In the first version, those shadows are allowed to go almost fully dark:
As a result, the main subject – the stairway – sits on top of a relatively featureless dark mass. This dark area is distracting, because it offers no detail and therefore looks out of place. It’s just this giant black thing in our line of sight, and the abrupt transition between the stairway and the void is jarring. Moreover, the dark background provides nothing with which to model the shape of the stairway's underside. This robs the image of depth, making it appear less three-dimensional than it could.
In the next version, the same shadows have been lightened:
Notice that the shadows still include areas of pure black (which is important to a full tonal range), but they transition to darkness much more gradually. The distracting void is gone, replaced by information that makes sense: the continuation of detail along the floor and the walls. The addition of light also models the underside of the stairway, making it look much more three-dimensional than before. The photograph as a whole better conveys the experience of the space, and provides a more complete picture of the designer’s vision (the designer in this case being Marcel Breuer).
The value of shadows can also be seen on smaller scales, as in this photograph of a living room. The darkest area is the fireplace on the right, and we see it first with very little detail:
Again, the lack of detail limits the apparent depth of the scene and creates an abrupt transition away from the brighter areas. Here’s the effect of adding shadow detail:
The difference is subtle but meaningful. As with the stairs, the added detail offers a smoother transition between light and dark, and contributes dimension to the scene.
There are a variety of techniques for optimizing shadow detail, both during capture and in post-production. A good photographer will understand how the shadows contribute to the image, and will account for them throughout the photographic process.
The next time you are evaluating (or taking) photographs, enjoy the highlights, but give the shadows their due. They are easy to overlook, but they are one of the keys to excellent photography.