When Autofocus Fails; Manual Focusing - Canon EOS-1DS Mark III Instruction Manual

When Autofocus Falls
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: Blue sky, solid-color walls, etc.
® Subjects in low light
® Extremely backlit and reflective subjects
Example: Car with a reflective body, etc.
® Overlapping near and far objects
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.83)
(2) Set the lens focus mode switch to <ME> and focus manually.
Manual Focusing
Set the hens focus mode switch to
<MF>.
_ Focus the subject.
® Focus by turning the lens focusing
ring until the subject looks sharp in
the viewfinder.
!f you PreSs the Shutter button halfway during manual fOcusing, th e active
A E point and the focus confirmation light <@> !n the viewfinderwi!! light
when focus is achieved,
86