This tutorial is an extraction from the Digital Photography Exposure For Dummies by Jim Doty, Jr. Visit Wiley Press for more information.
The direction of light describes where the light source is in relationship to you and your subject. It can change the look of your subject dramatically and therefore requires you to adjust your metering techniques somewhat. In the sections that follow, I describe the attributes of light based on the direction it's coming from and make some suggestions for using it.
How you choose to use the direction of light depends on which of the attributes of that particular light may or may not suit your purpose for a given image.
Photo by David Clapp.
You have frontlight when the light source is on the same side of your subject as you are, like when the sun is behind you or when the flash on your camera goes off.
Following are the characteristics of frontlight:
- It's very even.
- It doesn't add contrast to the subject.
- It shows colours and shapes well (unless the shapes are three-dimensional).
- It's good for a variations in subject tonality.
- It usually minimises texture.
- It can make subjects look flat and two-dimensional.
- It can be boring unless you have a subject with strong variations in colour or tonality.
Frontlight isn't great in all situations, but when it's soft, it's the best light for minimising imperfections in human skin. (Now you know why they put that huge light in front of you when you got your school pictures back in the day.)
Avoid taking photos of people when they're facing the sun. It may be frontlight, but it's too harsh.
Even though the majority of people take lots of frontlit photos, you'll be a better photographer, hone your exposure skills more quickly, and have more dramatic images if you take a higher percentage of backlit and sidelit photos.
If the sun or light source is to the side of your subject, you have sidelight – half the subject is lit and half is in shadow. The mix of light and shadow increases the contrast in the subject. The characteristics of sidelight are as follows:
- It's dramatic.
- It can cast long shadows when the sun is low in the sky.
- It makes subjects more three-dimensional.
- It's great at revealing texture.
- It can reduce the amount of colour information.
- It's harder to meter than frontlight.
Landscape photographers love sidelight, especially warm sidelight when the sun is low across the sky, because it creates long shadows across the frame.
Some subjects tend to lack colour interest, but they really pop with the contrast between light and shadow that sidelight creates.
You have backlight when the sun or other light source is behind your subject. It's bold and dramatic, but it's also a challenge to work with. Never fear, though. The photos you get when you use backlight are totally worth it.
Following are the characteristics of backlight:
- It creates dramatic contrast.
- It can significantly reduce the colour information in your subject.
- It emphasises shapes (so it's better for when you want shapes to take priority over colour).
- It can create dramatic rim lighting (a bright halo of light around your subject) when the sun is directly behind the subject.
- It creates a fresh look because most people rarely try backlighting.
- It can be used to create silhouettes.
- It darkens unlit areas of the subject.
- It's the most challenging type of light meter.
Of course, you can use light sources other than the sun to create backlighting.
You can use backlighting to dramatic effect when the sunlight hits the primary subject in your photo and the unlit background goes very dark. For example, if you shoot a bristly cactus when the sun is just above a mountain in the background but still lighting the cactus in the foreground, your backlit cactus, spines glowing in the sunlight, really pops against the backdrop of the mountain.
If the light is above your subject, like the sun in the middle of a summer day, you have toplight. Toplight can also happen inside when you have one overhead light source (as opposed to banks of overhead lights, when make the light less directional). The characteristics of toplight are as follows:
- Bright highlights on top of your subject
- Strong shadows below your subject
- Darker vertical surfaces, depending on the angle of the light source
- Dark shadows on faces
- Difficult metering contrasts
Toplight usually doesn't work because you don't get enough light on your subject. If you meter for the bright light on top of your subject, the rest of the subject winds up underexposed. If you meter the more shaded vertical sides of your subject, the top highlights get overexposed.
I don't usually like toplight because it's rarely useful and can create horrible, ghastly shadows in the eye sockets of your subjects. If you're photographing subjects in toplight, I strongly encourage you to use fill flash to fill in the shadows.