In life, we often think of things in terms of polar opposites: strong/weak, fast/slow, and light/heavy are examples. In many cases, we tend to think of one of the opposites as lacking something that the other opposite possesses. For example, a weak person is someone that lacks strength, a slow runner is someone that lacks speed, and a light object is something that lacks weight.
When carried into the field of photography, this mindset can lead us to think in terms of our own opposites: light and shadows -- not a bad way to view things. It is also easy to take the next step and think of shadows as simply a lack of light. Once this is done, shadows may seem to be less important. After all, we read and hear so much about light. For instance, landscape photographers write about magic hour light and fashion/glamour photographers talk about the great pains that they go to in order to get the studio lights just right. In the literature at least, it might seem that shadows are less important.
It would be easy to draw the conclusion that one need only focus on the light and let the shadows fall where they may. This would be a major mistake -- for light is nothing without shadows. Shadows are not simply a dark mass that borders the light. Rather, shadows are an entity as alive as the light. It is the shadows that shape the light, that draw attention to the light, and that integrate with the light to produce striking photographic opportunities. If we are to reach our full potential as photographers, we must think as much in terms of mastering the shadows as we do of mastering the light.
Perhaps, one of the most powerful uses of shadows is for the creation of contrast to produce a dramatic effect. Figure 1 shows an image that uses this approach. Shadows have been used three ways in this image. First, the clouds contain areas of light and areas of shadow. The dark areas of shadow in the clouds significantly increase the impact of the sky. Second, the shadows have been used to drop the foreground into silhouette. It would have been possible to use a split neutral density filter to bring out the detail in the foreground. However, any detail in the foreground would have competed for the viewers' attention. This would have decreased the impact of the image. Instead, the heavy shadow in the foreground serves to focus the viewers' attention on the sun and sky and to add a strong moodiness to the image. Third, the foreground shadow has created a strong diagonal line across the image. This serves to make the image a bit more dynamic.
In short, this image is totally dependent on the use of shadows. Had this image been shot a few minutes earlier when there was more light and less intense shadows, the impact of the image would have been significantly reduced.
Shadows can be effectively used to focus a viewer's attention. The shadows help focus the viewer's attention by removing detail from the less important parts of the image. Figure 2 uses shadow for this purpose. The lower part of the rock structure has very strong horizontal lines. These lines could compete with the vertical lines of the spires (at the top of the rock) for the viewer's attention. By waiting until the shadows covered the lower part of the rock (and reduced the visibility of the horizontal lines), this problem has been removed. Now, the spires are sandwiched between the dark rock and the relatively featureless sky (except for the small moon). Consequently, the viewers' attention is drawn to the one thing that stands out due to its contrast with the surrounding area -- the spires.
A powerful tool in photographic composition is the use of objects in an image to direct the viewer's eye. Shadows can be used very effectively for this purpose. More exactly, it is the objects that fall in shadow that can be used to direct the viewer's eye. Figure 3 shows an example of this technique. The rocks in the ocean point toward the sunset which is the center of focus of this image. These rocks serve to direct the viewer's attention to the sunset. The important point is that the rocks contain very little detail. This is due to the fact that the rocks are in shadow. Due to this, the rocks are effective at directing the viewer's eye without drawing much attention to the rock. If the rocks were not in shadow, the detail in the rock would distract the viewer's attention from the sunset. Consequently, the image would be weakened. In essence, the effectiveness of the rock in directing the viewer's eye is largely due to shadow.
One of the most common uses of shadows is for revealing form. This often involves the sun, at a low angle to the horizon, casting long shadows across the terrain. Figure 4 is an example of this use of shadow. This image relies almost totally on the shadows for its impact. In fact, there is actually very little detail in the image. Instead, it is the shadows that attract the viewer's attention. Had this image been shot with the sun directly overhead, there would be very little of interest in the image. Thus, in images of this type, the shadows sometimes become the center of interest.
Similar to revealing form, shadows can be used to reveal texture. Again, this often involves the sun, at a low angle to the horizon, casting shadows across the terrain. Figure 5 shows an example of shadows used to enhance detail. The ripples in this sand dune are barely noticeable when the sun is directly overhead. However, early in the morning or late in the afternoon, the low angle of the sun makes the ripples a predominant feature of the dunes. In fact, many photographers, myself included, travel to dunes specifically to capture the interplay of the shadows with the shapes and textures of the dunes.
Photographers are often urged to learn to read the light. However, reading the light is only half the challenge -- one must also learn to read the shadows.