Directional Light
Directional light, whether it comes from the sun, a flash unit, or a light bulb, is strong and full of contrast. The direction of the light determines where shadows and highlights will be, and how much of each will appear in the final image.
This kind of lighting casts heavy shadows and can create forceful pictures with strong impact and deep mood. Because it creates so much contrast, it can be difficult to properly expose film to capture the details in both light and dark areas. This is particularly true when using digital cameras, which are notorious for losing detail in the brightest part of the picture, a phenomenon known as blowing out the highlights. Careful attention must be paid to retain highlight detail in these instances.
In the color insert, the photo of snowy dunes at sunset took advantage of a very fleeting moment of opportunity for dramatic directional lighting, capturing a unique quality of light that only lasts a few minutes at that time of year.
Light from the front is the type of lighting we're most familiar with, as so many pictures are taken with it. Shots taken with this kind of lighting don't have shadows. Since shadows create depth, pictures lit from the front also tend to look flat. People in front-lit pictures often look uncomfortable and squinty because the light is shining directly into their eyes.
Front lighting is often referred to as flat lighting, which refers to the flat-ness caused by the lack of shadows. Side lighting is generally preferred for the added drama it brings. An example would be a shot taken when the sun is partly rising or setting and directly to the left or right of the subject. This lighting gives subjects depth.
You'll see a lot of front lighting in old photographs. The first lenses and films were substantially slower, and it took a great deal of light to render correctly exposed images. Early photographers were told to shoot with the light behind them so it would illuminate the front of their subjects. Today, front lighting is no longer necessary with most cameras. However, since it's the type of lighting we're most familiar with, you'll still see it used in many pictures, and you probably use it yourself.
Backlighting puts the main source of light behind the subject, shining toward the camera. Backlit scenes can be extremely dramatic and beautiful, but they can also be rather difficult to expose correctly. If the camera's light meter only measures the light behind the subject, then the subject will be underexposed and will appear as a silhouette, which may actually be the desired effect. If it isn't, readings must be balanced between the subject and the light behind it so the front of the subject is properly exposed. In digital photography, an underexposed photo with the foreground subject appearing too dark can be adjusted with image manipulation software to bring out the shadow detail that was lost. Likewise, overexposed subjects can often be darkened.
FIGURE 10-1 In this backlit image, the bright sunlight behind the semi-transparent flower petals delicately highlights the detail and delicacy of their fragile form, which shows it off to good advantage.
Also known as split lighting, side lighting is created when you take a picture with the lighting source at one side or the other. Since it illuminates one side of the subject, it can create fairly dramatic effects. Side light also emphasizes texture, shape, and form. Crosslighting is created by using artificial light to shine on an object from both sides. It's often used in commercial product photography.
Up-lighting is created when the subject is lit from below. This can create dramatic images, but be warned that this sort of lighting is usually the least flattering for pictures of people, as the main light for portraits should not come from below the horizon. Sunlight bouncing up from the pavement or other sources is not flattering unless your subject is looking down in the direction of the light.
Down-lighting is created when the subject is lit directly from above. It's not flattering for most subjects, but some scenery, especially when captured from a distance, will look good with this type of lighting. When taking portraits, you'll find that down-lighting casts shadows under the subject's eyebrows and chin, making a person's eyes appear as dark splotches.
The opposite of directional light, nondirectional light is created when light comes from all directions and casts no shadows. It can be created naturally by mist or clouds in an overcast sky, but you can also create artificial nondirectional light yourself with a sheet or a reflector covering the entire subject so no obvious direction of light is evident in the scene.
