Pentax 645N2 - Manual (Page 65)

63
ADV
ANCED OPERA
TIONS
HARD-TO-AUTOFOCUS SUBJECTS
The autofocus system is highly precise, but not per-
fect. Depending on the brightness, contrast, shape,
and size of your subject, the autofocus system may
not operate. In such a case, use the focus-lock
technique (see page 60.) on another subject that is
the same distance away, or set the lens to use the
manual focus mode to focus the lens on the subject
with the aid of the matte field in the viewfinder.
Subjects which may fool the autofocus system
include:
a) Extremely low-contrast subjects such as a white
wall in the autofocus frame [ ].
b) Subjects which don’t reflect much light in the aut-
ofocus frame [ ].
c) Subjects which are moving too fast.
d) Multiple subjects in the foreground and back-
ground of the autofocus frame [ ].
e) Subjects positioned against reflected light or
strong backlight or with extremely bright back-
grounds.
1 2
How to focus on the subject with the aid of the
matte field
1. Set the lens in the manual focus position.
2. While looking through the viewfinder, turn the
focusing ring to the right or left until the
image in the viewfinder is clearest.
MF AF 22 16 8 4 22 16 8 4
f t m 1 0 1 5
A 2 2 16 11 8 5.6 2.8