When Autofocus Fails (Manual Focusing) - Canon EOS 1D MkII Instruction Manual

When Autofocus Fails (Manual Focusing)

Autofocus can fail to achieve focus (the focus confirmation light <
blinks) with certain subjects such as the following:
Subjects difficult to focus
(a) Low-contrast subjects
Example: Blue sky, solid-color walls, etc.
(b) Subjects in low light.
(c) Extremely backlit and reflective subjects
Example: Car with a reflective body, etc.
(d) Overlapping near and far objects
Example: Animal in a cage, etc.
(e) Repetitive patterns
Example: Skyscraper windows, computer keyboards, etc.
In such cases, do one of the following:
(1) Focus an object at the same distance as the subject and lock the
focus before recomposing.
(2) Set the lens focus mode switch to <
If focus cannot be achieved with the AF-assist light of a Speedlite or ST-E2,
select the center AF point. An off-center AF point may not be able to achieve
focus.
g
> and focus manually.
o
>
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