SIGMA SD1 - Manual (Page 48)

47
A APERTURE PRIORITY AE
After you set the aperture value, the camera will determine the appropriate
shutter speed. If you select smaller apertures, depth of field will be greater.
Larger apertures tend to blur the background, as depth of field will be
shallower.
1
Set the D-dial to “Drive–Area” (P.13).
2
Set the Mode dial to the A position.
3
Press the shutter button halfway to verify
focus, and select the desired aperture
value by turning the A-dial (
) or S-dial
( ).
4
Verify the setting in the viewfinder.
If the appropriate shutter speed is outside
the range of suitable combinations due to
the subject being too bright or too dark,
the shutter speed indicator will blink. If the
subject is too bright, set the aperture value
to a smaller one (larger F-number). If the
subject is too dark, set the aperture value
to a larger one (smaller F-number) until
the indicator stops blinking.