Canon EOS Rebel T4i Instruction Manual - Page 100

Subjects Difficult to Focus Autofocus can fail to achieve focus (viewfinder's focus confirmation light blinks) with certain subjects such as the following: Very low-contrast subjects (Example: Blue sky, solid-color walls, etc.) Subjects in very low light Extremely backlit or reflective subjects (Example: Car with a highly reflective body, etc.) Near and far subjects covered by an AF point (Example: Animal in a cage, etc.) Repetitive patterns (Example: Skyscraper windows, computer keyboards, etc.) In such cases, do either of the following: (1) With One-Shot AF, focus an object at the same distance as the subject and lock the focus before recomposing (p.61). (2) Set the lens focus mode switch to and focus manually. For subjects difficult to focus during Live View shooting with [u+Tracking], [FlexiZone - Multi], or [FlexiZone - Single], see page 159. MF: Manual Focusing 1 Set the lens focus mode switch to . Focusing ring 2 Focus the subject. Focus by turning the lens focusing ring until the subject looks sharp in the viewfinder. If you hold down the shutter button halfway during manual focusing, the AF point achieving focus will light up briefly in red, the beeper will sound, and the focus confirmation light in the viewfinder will light up. 100