Giving Your Subject Some Headroom
The term headroom refers to the amount of space between the top of your subject and the top edge of your frame—if you're photographing people, it's the amount of space above the subject's head. (Hence the word headroom.) However, keep in mind that the subject isn't always a person; you can have headroom above a building, a sign, a bowl of fruit, an airplane, and so on. Headroom is the space above what's important in your shot.
The right amount of headroom gives you a shot that's easy to view (see Figure 3). Too much headroom gives the scene dead space; viewers find themselves drawn to that space (and away from your subject), looking for something of value. Too little headroom cuts off the top of your subject, or puts the subject awkwardly close to the top of the frame. Too little headroom can be especially uncomfortable for the viewer, because the subject can seem crushed by the top of the frame.
Figure 3 The right amount of headroom (right) will give a relaxed feel to the shot, neither too spacious (left), nor too cramped (center).
The right amount of headroom will change slightly with the type of shot you're angling to capture. A very tight close-up might have no headroom at all; an extremely wide shot might have quite a bit of headroom. Here's a rough guide for shooting people: If you follow the rule of thirds, putting the subject's eyes on the top horizontal axis should give you a comfortable amount of headroom. To find just the right amount more organically, start close to your subject and zoom out (or move away) until the look feels right.