Canon EOS 550D Instruction Manual page 27

Using AF to Focus
Live Mode and _ (Face Detection) Live Mode Notes
AF operation
® Focusing wili take siightiy ionger,
® Even when focus has been achieved, pressing the shutter button
haifway wiii focus again,
® The image brightness may change during and after the AF
operation,
® if the iight source changes whiie the Live View image is displayed,
the screen might flicker and focusing can be difficuit, if this happens,
stop the Live View shooting and autofocus under the actuai iight
source first,
® if you press the <Q> button in the Live mode, the image wiii be
magnified at the AF point, if focusing is difficuit in the magnified view,
return to the normal view and autofocus, Note that the AF speed
may differ between the normal and magnified views,
® if you autofocus in the Live mode's normal view and then magnify
the image, the focus might be off,
® in the _ Live mode, pressing the <Q> button will not magnify the
image,
peripheral subject and the target subject is slightly out of f0cus, aim the
center AF point over the subject to focus, then take the picture.
The AF-assist beam wi!! not be ernitted,
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