Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 404)

3.
Move the magnified area.
Use < > to move the magnified area into position for focusing.
To return the magnified area to the center of the screen, press < >
straight in or press the < > or < > button.
4.
Focus manually.
While looking at the magnified image, turn the lens focusing ring to
focus.
After achieving focus, press the < > button to return to the normal
view.
Note
In magnified view, the exposure is locked.
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