Canon PowerShot SX100 IS User Manual page 101

The AF frame appears as follows when the shutter button is
pressed halfway.
- Green
- Yellow
- No AF frame : Focusing difficulty ([Face Detect] option)
Face Detect Feature
Maximum of three AF frames will be displayed at the position of the
face the camera recognizes. At this point, the frame the camera
judges to be the main subject appears in white while the others
appear in gray. When the shutter button is pressed halfway and the
camera focuses, up to 9 green AF frames may appear.
The camera will shoot using [AiAF] not the [Face Detect] function if
a white frame fails to appear and only gray frames display, or if a
face is not detected.
The camera may mistakenly identify non-human subjects as a face.
In this case, select [Center].
In certain cases, faces may not be detected.
Examples:
- If faces are at the edge of the screen, or appear extremely small,
large, dark or bright, relative to the overall composition.
- Faces turned to the side or at a diagonal, or faces with a portion
hidden.
: In focus
: Focusing difficulty ([Center] option)
Various Shooting Methods
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