The importance of Shadows

Shadow is an important, though often neglected, element of composition. Used carefully and creatively it not only gives a great sense of depth and form but may also provide an additional area of interest to complement the main subject of the picture. The influence of shadow is so strong that it should be considered as carefully as the main subject itself when composing the picture within the viewfinder.

How camera registers shadow:
The human eye is extremely versatile and has a remarkable ability to cope with an extreme range in the brightness of light. It can see detail both in bright sunlight and in deep shadow. This is called the brightness range and the standard for the human eye is measured as 1000 to 1.

Black and white film, however, has a much smaller brightness range. It cannot compensate for great changes in the brightness of light and only registers detail through a range of 128 to 1. With a good black and white film developed in a standard developer this is equivalent to exposure latitude of seven f stops.

Color film has an even smaller brightness range. Slow transparency color film has a range of only 32 to 1, equivalent to about five f stops.

Some digital cameras at ISO 100 have a dynamic range of about 446:1. That means the digital imager captures and delivers an image made from 8.8 stops of brightness.

What all this means, more simply, is that when you are looking at a subject that is unevenly lit you will be able to see detail in both the well illuminated areas (highlights) and the areas of relative darkness (shadows). The camera, however, will not be able to do so, and if you expose for the highlights the shadows will come out very dense and almost totally without detail. If you do the opposite and expose for the shadow areas, then the highlights will be over-exposed and the detail washed out.

There is really no easy way of increasing the brightness range of your camera but the very limitations can be used to advantage by getting rid of an unwanted background, for example.

Contre-jour
The effect of taking your picture into the light and exposing for the shaded side of your subject is known as contre-jour. With the correct exposure you get a soft image with a ring of light, or halo effect, around the subject. The background, however, will be heavily over-exposed and will almost disappear.

Calculating exposure
Just what exposure you give your subject depends to a great extent upon the importance that you want shadow to play in the composition. If you expose for the highlight areas in an unevenly lit subject the shadows will be under-exposed and lacking in detail. Taking an average of the readings from both highlight and shadow areas should give you acceptable detail throughout.

You may find that when taking light readings from more than one area of a subject a 'spot meter' or hand-held meter is more accurate than using the integrated light meter in your camera. But if you don't have a hand-held meter move the camera in close to the light and dark areas in turn before assessing the exposure for the effect you want.

Using shadow:
In their simplest form shadows can be used to give information in a picture emphasizing the shape and form of a subject and indicating the time of day, the direction of the light and even the state of the weather. Used imaginatively they can also create a powerful image.

• Silhouetted shapes can add drama to a composition.
• Unwanted foreground or background detail can be played down by exaggerating the shadow area.
• An interesting shadow can actually form the main subject of your picture.
• A strong directional shadow can be used as an element of balance and also of perspective.
• The dappled shadow beneath a tree can give the subject an abstract effect.
• Shadow can provide a neutral setting to enhance the effect of bright color or to separate areas of conflicting color.
• Strong shadows can emphasize a shaft of light falling through a break in the clouds or between buildings in an urban landscape.

Look out for these opportunities and take advantage of them. Usually the darker the shadow the more powerful is the effect. But in color digital photography a soft shadow very often brings out a range of subtle hues not found in brighter light. So, look for pale shadows as well as hard ones. The important thing is to be aware of shadow in the first place. Once you have noticed it the possibilities for its creative use in your pictures are practically endless.