f
: Changing the Depth of Field
168
To obtain a correct flash exposure, the flash output will be automatically
controlled (autoflash) to match the set aperture. The shutter speed will
be set automatically within the range of 1/200 sec. - 30 sec. to match
the brightness of the scene.
In low light, the main subject is exposed with the autoflash, and the
background is exposed with a slow shutter speed set automatically. The
picture comes out with the standard exposure for both the subject and
background with a touch of the atmosphere (automatic slow-speed
flash sync). If you are handholding the camera, keep it steady to
prevent camera shake. Using a tripod is recommended to prevent
camera shake.
To prevent a slow shutter speed, under [
z
2: Flash control
], set
[
Flash sync. speed in Av mode
] to [
1/200-1/60sec. auto
] or [
1/200
sec. (fixed)
The aperture opening (diaphragm) changes only at the moment when
the picture is taken. Otherwise, the aperture remains fully open.
Therefore, when you look at the scene through the viewfinder or on the
LCD monitor, the depth of field will look narrow.
Press the depth-of-field preview button
to stop down the lens to the current
aperture setting and check the depth of
field (range of acceptable focus).
D
Using the Built-in Flash
Depth-of-Field Preview
N
While looking at the Live View image (p.196) and holding down the depth-of-
field preview button, you can see how the range of acceptable focus will
change as you adjust the aperture.