When Autefocus Fails - Canon EOS Rebel XS Instruction Manual

W he n A u tofo cus Fai I s __yyy_yyyyyyymE_
Autofocus can fail to achieve focus (the focus confirmation light <0>
blinks) with certain subjects such as the following:
Subjects difficult to focus
Low-contrast subjects
Example: B_ue sky, solid-color walls, etc
Subjects in _ow 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
_ ]f an Extender (sold separately) is attached and the maximum apertur e of
the lens is f/5.6 or smaller (larger f/r_umber), AF wilJ not be possibJe
(except Live mode AF), For details_ see the Extender's [nstructi0n
mar_uaL
For the cases AF £aq fai! to ach!eve foc£s w_th Qve m£de AF, see
page 106.
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