Sony a (alpha) DSLR-A100 Operating Instructions Manual page 52

(Wide AF area)
(Spot AF area)
(Focus area selection)
52
The camera determines which of the nine local focus frames is
used in focusing within the wide focus frame.
• When you press the shutter button halfway down, the frame
used in focusing is illuminated briefly.
• You can switch to spot focus frame if the desired frame is not
used in focusing. Press the spot AF button at the center of the
controller to focus the center of the screen, and press the shutter
button all the way down without releasing the spot AF button on
the controller to take a picture.
The camera uses the spot focus frame exclusively.
• When you look into the viewfinder, the spot focus frame is
illuminated briefly.
Choose a local focus frame from the nine frames.
Press the corresponding one of the controller, and the local focus
frame in the specified direction is used in focusing. (Eight
directions are available.) Press the spot AF button at the center to
use the spot focus frame in focusing.
• When you look into the viewfinder, the selected focus frame is
illuminated briefly.
• After shooting, frame selection is still available. Be sure not to
press the controller unless it is necessary.
( : The default setting)
Wide focus frame
Spot focus frame
Local focus frame
Spot focus frame