SIGMA SD9 - Manual (Page 46)

FOCUS LOCK
If you want to take the picture of a subject, which is out of the focus detecting
area, use focus lock function. This function can be used only in
(single AF
mode)
1
Compose the desired focusing subject in the center of viewfinder and then press the
shutter button “Half-way”.
2
Keep the shutter button depressed “Half-way” while you compose the picture as
desired. Then press the shutter button the rest of the way to take picture.
MANUAL FOCUS
In situations, where autofocus or focus lock are not effective, you can focus
manually.
1
Set the focus mode switch, on the lens to the M
position (AF mode mark will disappear from the
LCD panel).
2
While looking through the viewfinder, turn the
focusing ring on the lens until you get a clear
sharp image.
When you use a lens, which has maximum aperture of F5.6 or faster, the focus
indicator in the viewfinder will appear, when correct focus is attained.
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