Af-Assist Illuminator; Situations Where Autofocus May Not Work As Expected - FujiFilm FinePix S3 Pro Owner's Manual

AF-ASSIST ILLUMINATOR

When the subject is dark and the shutter button is pressed down halfway, the camera's AF-assist
illuminator automatically turns on and enables autofocus operation in a dark environment.
Approx. 0.5-3 m
(1.6-9.8 ft.)
CSM 15: AF-assist illuminator can be cancelled (➡P.112).
When the AF-assist illuminator is used continuously, illumination is limited temporarily to protect
the firing tube. The illumination restarts after a few moments. Also, when the AF-assist illuminator
is used repeatedly in a short period of time, be careful not to touch the AF-assist illuminator lamp
because it may have become hot.
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Nikon flash units and active assist illuminator
If you use an SB-28/28DX, SB-27, SB-26, SB-25, SB-24, SB-800 or SB-600 Nikon flash to take
pictures when the conditions for active assist illuminator are met, the active assist illuminator on the
Nikon flash automatically fires. With other Nikon flash models, the AF-assist illuminator on the camera
automatically lights.
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Lenses for which vignetting occurs
h Autofocus using the camera's AF-assist illuminator cannot be performed due to vignetting with
following lenses at shooting distance within 1m (3.3 ft):
i AF Micro 200 mm f/4 IF-ED
i AF-S 17-35 mm f/2.8 IF-ED
i AF 18-35 mm f/3.5-4.5 ED
i AF 20-35 mm f/2.8 IF
i AF 24-85mm f/2.8-4D
i AF-S DX 18-70mm f/3.5-4.5G
i AF-S VR ED 24-120mm f/3.5-5.6G
h At shooting distances of 2 meters or less, the AF-S DX ED 17-55mm f/2.8G (IF) cannot be used for
autofocus photography where the AF-assist illuminator is used.
h Autofocus using the camera's AF-assist illuminator cannot be performed due to vignetting with AF-S
80-200 mm f/2.8 IF-ED, AF 80-200 mm f/2.8 ED, AF VR 80-400 mm f/4.5-5.6 ED, AF-S VR ED 70-
200mm f/2.8D and AF-S VR ED 200-400mm f/4G.
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AF-assist illuminator automatically turns on in the
following situations:
Focus mode is Single AF servo, AF Nikkor lens is
used, subject is dark and center focus area is
selected or Dynamic AF Mode with Closest Subject
Priority is activated.
Focal length of the usable AF Nikkor lens is 24-200
mm and the distance range of the AF-assist
illuminator is approx. 0.5-3 m (1.6-9.8 ft.).
◆
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i AF 24-120 mm f/3.5-5.6 IF
i AF-S 28-70 mm f/2.8 IF-ED
i AF Micro 70-180 mm f/4.5-5.6 ED
i AF 24-85 mm f/2.8-4
i AF-S DX ED 12-24mm f/4G
i AF-S ED 24-85mm f/3.5-4.5G
i AF ED 28-200mm f/3.5-5.6G

SITUATIONS WHERE AUTOFOCUS MAY NOT WORK AS EXPECTED

Autofocus may not work as expected in the following situations. In such situations, focus manually
using the clear matte field or focus on a different subject located at the same distance, use AF lock
(➡P.40) then recompose.
Low-contrast scenes
For example, where the subject is wearing clothing
the same color as a wall or other background.
Scenes with subjects within the focus brackets
located at different distances from the camera
For example, when shooting an animal in a cage or
a person in a forest.
Patterned subject or scene
For example, building windows.
Scenes with pronounced differences in brightness
within the focus brackets
For example, when the sun is in the background
and the main subject is in shadow.
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