Canon EOS 7D - Manual (Page 148)

148
Using AF to Focus
3
Focus the subject.
Aim the AF points over the subjects
and press the shutter button halfway.
X The Live View image will turn off, the
reflex mirror will go back down, and
AF will be executed.
X When focus is achieved, the beeper
will sound and the Live View image
will reappear.
X The AF point used to focus will be
displayed in red.
4
Take the picture.
Check the focus and exposure, then
press the shutter button completely to
take the picture (p.136).
You cannot take a picture during autofocusing. Take the picture only while
the Live View image is displayed.