Canon eos rebel T2i - Manual (Page 120)

120
You can magnify the image and focus precisely manually.
1
Set the lens focus mode switch to
<MF>.
Turn the lens focusing ring to focus
roughly.
2
Move the magnifying frame.
Press the <S> key to move the
magnifying frame to the position
where you want to focus.
To return the magnifying frame to the
center, press the <L> button.
3
Magnify the image.
Press the <u> button.
X The part within the magnifying frame
will be magnified.
Each time you press the <u> button,
the view will change as follows:
4
Focus manually.
While looking at the magnified image,
turn the lens focusing ring to focus.
After achieving focus, press the <u>
button to return to the normal view.
5
Take the picture.
Check the focus and exposure, then
press the shutter button to take the
picture (p.108).
Focusing Manually
Magnifying frame
AE lock
Magnified area position
Magnification
5x 10x Normal view
COP
Y