Depth-Of-Field Preview - Canon EOS REBEL T6i Instruction Manual

f: Changing the Depth of Field
D Using the Built-in Flash
To obtain a correct flash exposure, the flash output will be set
automatically to match the set aperture (autoflash exposure). The
shutter speed will be set automatically between 1/200 sec. - 30 sec. to
suit the scene's brightness.
In low light, the main subject is exposed with the auto flash metering,
and the background is exposed with a slow shutter speed set
automatically. Both the subject and background look properly exposed
with a touch of 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 a slow shutter speed, under [z1: Flash control], set
[Flash sync. speed in Av mode] to [1/200-1/60sec. auto] or [1/200
sec. (fixed)] (p.174).
Depth-of-Field PreviewK
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.
While looking at the Live View image (p.192) 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.
154
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).