Pentax Optio S5z Operating Manual page 76

Changing the Focusing Point
In Focusing Area mode, you can change the focusing point by moving
the focus frame.
1
In (Focusing Area) mode, press the four-way controller
(2345).
Moves the focus frame [ ] (Focusing area).
2
Press the shutter release button halfway.
The focus frame is fixed in its new position. Press the OK button again
to change the setting of the focusing area.
4
When you use the Focusing Area mode with the comment space,
make sure that the focus frame and the comment space do not
overlap one another. (
74
Troubleshooting "Subject is not in focus" 1p.157
1 p.62)