Pentax ist - Manual (Page 100)

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1
Set the focus mode switch
to .
2
Frame the subject. If the
subject you wish to focus
on is not on any of the
focus points, you can use
focus lock.
The figure to the right shows the
person is not focused and the
background is focused instead.
ABOUT FOCUSING
Using the Focus Lock
If the subject is not covered by any of the focus points, the
camera cannot automatically focus the subject. In this situation,
you can aim the focus point on the subject, use focus lock, then
recompose the picture.