Nikon D200 - Manual (Page 69)

59
Ref
er
enc
e
—
F
ocus
Under the conditions described above, the optional SB-800 and SB-600 Speed-
lights and SU-800 wireless Speedlight commander will provide active AF illumi-
nation for the following focus areas:
AF lens focal length Normal frame (11 areas) Wide frame (7 areas)
23–34 mm
35–70 mm
71–105 mm
With other Speedlights, the camera AF assist illuminator will be used.
Getting Good Results with Autofocus
Autofocus does not perform well under the conditions listed below. If the cam-
era is unable to focus using autofocus, use manual focus (
60) or use focus lock
( 56) to focus on another subject at the same distance and then recompose
the photograph.
There is little or no
contrast be tween
the sub ject and the
back ground
Example: sub ject is the same col or as the
back ground.
The focus area
con tains ob jects at
diff er ent dis tanc es
from the cam era
Example: sub ject is in side a cage.
The subject is dom-
i nat ed by reg u lar
geo met ric pat terns
Example: a row of windows in a skyscraper.
The focus area
con tains areas of
sharp ly con trast ing
bright ness
Example: sub ject is half in the shade.
The subject many
contains fi ne details
Example: a fi eld of fl owers or other subjects
that are small or lack variation in brightness.
The subject appears
smaller than the
focus area
Example: focus area contains both fore-
ground subject and distant buildings.