Depth of field continually changes as you focus at different distances, select different lenses, or zoom in or out. This is something you quickly become accustomed to, but it can’t be ignored. Focusing is much easier in longer shots and more complicated with close-up shots. You shoot two people speaking, yet can get a sharp image of only one of them at a time. In very large close-ups, focusing can be so critical that only part of a subject is sharp, while the rest is completely defocused. Figure 7.6 illustrates some of the solutions to this dilemma.
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