The Canon EOS Digital Rebel XSi/450D Companion

CHAPTER 6

FOCUS MODES

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When all the focus points land on contrastless fog, the camera can’t set focus.

Tilt down so that the camera’s focus spots are on the contrasty bridge. Press the

shutter button halfway to lock focus; then reframe and take the focused shot.

WARNING: Use Something at the Same Distance to Set Focus

Remember, though, for this to work, you must focus on something that’s at

the appropriate distance. Don’t lock focus on something in the foreground or

way in the distance. When you reframe, your camera will be focused at the

wrong point.

Low-Light Autofocus Problems

Sometimes your scene lacks contrast because it’s too dark. When this happens,

the camera may have trouble locking focus. If you hear the camera focus in and

out for a while and it still doesn’t lock focus, then probably the scene is too dark

for the autofocus mechanism to work. To give the camera some help, pop up the

built-in flash. Now when you press the shutter button halfway down, the camera

PROGRAM MODE

FOCUS MODES

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will fire some quick flash bursts to illuminate the scene. is extra light can help

it lock focus. If you don’t want the flash to fire during the shot, keep the shutter

halfway down while you close the flash. Now you’ll have a locked focus and can

shoot without flash.

Obviously, this focus-assist ...