Solving autofocus problems

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When you shoot in the fully automatic modes, the camera typically focuses on the closest object. If the camera insists on selecting an autofocus point that isn't appropriate for your subject, the easiest solution is to switch to manual focusing and be done with it. Chapter 1 shows you how. Or you can use the advanced exposure modes, which enable you to select a specific autofocus point. Chapter 6 explains that option plus a few other tips for getting good autofocus results.

✓ Shooting moving subjects: If the focus indicator doesn't light but you hear a continuous series of beeps, the camera's telling you that it detected motion in the scene. To accommodate that motion, it shifts to an autofocusing mode called AI Servo. (The AI stands for artificial intelligence.) In this mode, the camera focuses continually after you press the shutter button halfway. As long as you keep the subject within one of the autofocus points, focus should be correct. See Chapter 6 for more tips about this and other autofocus modes.

✓ Locking exposure: By default, pressing the shutter button halfway does not lock exposure along with focus. Your camera instead continues metering and adjusting exposure until you fully depress the shutter button. If you want to lock exposure, you must use an advanced exposure mode; see Chapter 5 for help.

✓ Changing the Drive mode setting: In most of the automatic exposure modes, your camera automatically sets the Drive mode to Single, which records a single image with each press of the shutter button. But in Portrait and Sports modes, the camera instead selects Continuous mode, which records pictures as long as you hold down the shutter button. You can change the Drive mode to a Self-Timer or Remote Control setting for any exposure mode, however. See the end of this chapter for details.

✓ Shooting in Live View mode: Unfortunately, you can't use Live View mode, which enables you to frame your image using the camera monitor instead of the viewfinder. If you want to take advantage of Live View, you must switch to an advanced exposure mode. Chapter 4 provides a primer on Live View shooting.

Memory card access lamp

Figure 2-4: The card access lamp lights while the camera sends the picture data to the card.

Memory card access lamp

Figure 2-4: The card access lamp lights while the camera sends the picture data to the card.

More focus factors to consider

When you focus the lens, either in autofocus or manual focus mode, you determine only the point of sharpest focus. The distance to which the sharp-focus zone extends from that point—what photographers call the depth of field — depends in part on the aperture setting, or f-stop, which is an exposure control. Some of your camera's fully automatic exposure modes are designed to choose aperture settings that produce a certain depth of field.

The Portrait setting, for example, uses an aperture setting that shortens the depth of field so that background objects are softly focused — an artistic choice that most people prefer for portraits. On the flip side of the coin, the Landscape setting selects an aperture that produces a large depth of field so that both foreground and background objects appear sharp.

Another exposure-related control, shutter speed, plays a focus role when you photograph moving objects. Moving objects appear blurry at slow shutter speeds; at fast shutter speeds, they appear sharply focused. On your camera, the Sports shooting mode automatically selects a high shutter speed to help you "stop" action, producing blur-free shots of the subject.

A fast shutter speed can also help safeguard against allover blurring that results when the camera is moved during the exposure. The faster the shutter speed, the shorter the exposure time, which reduces the time that you need to keep the camera absolutely still. For a very slow shutter speed, using a tripod is the best way to avoid camera shake.

Keep in mind, too, that the range of f-stops and shutter speeds the camera can select in any of the creative scene modes depends on the lighting conditions. When you're shooting at night, for example, the camera may not be able to select a shutter speed fast enough to stop action even in Sports mode. If you want to manipulate focus and depth of field to a greater extent than the automated exposure modes produce, visit Chapter 6. For an explanation of the role of shutter speed and aperture in exposure, check out Chapter 5.

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