Digital Photography Composition For Dummies

exposure. If you stay in the same spot and have the person step out half the distance between you and the wall and take another shot, the results will be different: The wall will become softer because your focus is now farther from it. The wall also will become darker. Light falls off at a certain rate as it travels through space, and in this case it would lose one stop of intensity by the time it traveled from the person to the wall. The person would be exposed properly and the wall would be one stop underexposed.

In some situations, you may prefer that your background be out of focus but exposed properly with the subject. In that case, bring the subject away from the background and rely on available light instead of an on- camera flash.

Zooming in to reveal details

A zoom lens can come in handy when you're shooting on the fly or when you can't move closer to your subject. When zooming in isn't your only option, however, you have to decide whether to zoom in or physically move in.

A major misconception in the world of photography is that the focal length of a lens can change perspective. This simply isn't true. Only you can change your perspective.

Try following these steps to see what I mean:

1. Set up your camera with a subject in front of a background that includes various elements at various distances.

A city street is a good choice.

2. With a zoom lens at its widest focal length, take a photo of the subject.

3. Without moving the camera or any elements in the frame, zoom in to the lens' longest focal length and take another photo of the subject.

If you look at the images from Steps 2 and 3 on your computer side by side, you may appear to have two different perspectives. In reality, though, you have two different crops. To prove this to yourself, crop into the photo taken with the wide focal length until the crop matches that of the photo taken with the long focal length. Compare the images, and you see that the compositions are the same. The relationships of the subject and the other elements have stayed the same, so the perspective hasn't changed.

The reason photographers often believe focal length has something to do with perspective is because they typically use telephoto lenses from far away and wide angles from nearer perspectives. Focal length may cause

a photographer to change perspective, but it doesn't change perspective itself. So, if you feel that your perspective is perfect but you want more visible detail, you can zoom in. When you do so, you lose background information in two ways:

I•»' You magnify your subject, making your depth of field shallower. •»' You eliminate much of the surrounding background details.

If you want a clearer and more descriptive background, move in and use a wider angle. As you get closer to your subject, the background elements get smaller. By using a wider lens, you see more of the background and surrounding details, and your subject isn't magnified in the lens. Therefore the depth of field is greater.

Macro photography is the art of magnifying the subject as much as possible while keeping sharp focus on that subject. With this technique, however, the background becomes much less focused. As you can see in Figure 8–4, the depth of field becomes extremely shallow with this much magnification.

135mm (with 25mm extension tube), I/SO sec, f/6.3,400

Figure 8–4: Place your focus where you want it when you use a lens or perspective that magnifies your subject.

Using focal length to achieve your goals

In addition to being a tool that helps you control depth of field, focal length is useful in finding the right perspective. Having depth (the illusion of three-dimensional space) in your photographs is a great way to draw viewers in. Remember: Don't confuse depth with depth of field, which is the amount of sharp detail you have in an image. (See Chapter 7 for more details.)

Depth occurs when a viewer can sense the distance between different elements in a photograph. Wide- angle lenses enable you to incorporate more of a scene into your frame, which helps to maximize the illusion of depth. The wide angle enables you to include more physical space in the frame, so naturally it gives you the potential to create photographic depth when you combine it with a high angle. Figure 8–5 represents an example of depth in a scene created by using a wide-angle lens and a high perspective or angle.

24mm, 1/250 sec, f/l 1,100

Figure 8–5: Shooting down from a high angle with a wide-angle lens can create an image with depth.

Setting the camera high on a tripod and pointing it straight out and parallel to the ground gives you a frame with a centered horizon line and a lot of sky. The film plane (the plane that your digital sensor exists on; see Chapter 3) is perpendicular to the ground, limiting the focus you can achieve in the shot, regardless of your aperture. In most cases you can lower the angle of the camera to eliminate some of the sky and include more of the foreground. The foreground then contains a lot of detail because it's closest to the lens. And if you choose it well, the foreground then provides purpose to your image.

When the film plane is closer to parallel with the ground, you can achieve focus on details in more of the frame. Shooting with a vertical crop instead of a horizontal crop can increase depth even more. You lose some of the surrounding details, but you then have the ability to include even more of the foreground in the frame. A horizontal crop works great for depicting expansive areas, and a vertical crop works for creating depth.

In many cases, depth isn't the most important factor when composing an image. Consider, for example, when you take a portrait of a person's face. If you get in close to someone's face with a wide-angle lens and take a picture, your subject's nose will appear much larger in the image than it does in reality. When taking a headshot or close-up portrait in the 35mm format, choose a focal length of 70mm or higher. Doing so proportions the features of the face evenly.

Rotating your Camera to Create Unusual Angles

Imagine you're in position with your camera, and your subject is in place. You're satisfied with the perspective as far as the relationships of the elements within the frame, but suppose you want a more interesting composition. Maybe it seems that the situation needs something different to tell the whole story, or maybe you're just bored with the traditional composition that you see through the viewfinder.

One way to take charge of this situation is to rotate your camera in order to depict the relationships of the elements in the scene in a different way. The difference can be obvious or subtle. Rather than changing the relationships of the elements to one another, you change their position in the frame, which ensures that viewers see them differently.

In the following sections, I show you different ways to rotate your camera so you can portray a scene differently without changing the relationships of the elements to one another.

Putting the subject off center