Cannon 500D instruction manual When Autofocus Fails, Subjects difficult to focus, 192

When Autofocus Fails

Autofocus can fail to achieve focus (the focus confirmation light <o> blinks) with certain subjects such as the following:

Subjects difficult to focus

Low-contrast subjects

(Example: Blue sky, solid-color walls, etc.) Subjects in low light

Extremely backlit or reflective subjects (Example: Car with a 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 one 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.46).

(2)Set the lens focus mode switch to <MF> and focus manually.

If an Extender (sold separately) is attached and the maximum aperture of the lens is f/5.6 or smaller (larger f/number), AF will not be possible (except Live mode/uLive mode AF). For details, see the Extender’s instruction manual.

For the situations where AF can fail to achieve focus with Live mode/u Live mode AF, see page 115.

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