Canon EOS 5D Mark III, Instruction Manual, Page: 327 / 404

327
8 2: Custom Controls
During flash photography, pressing the button assigned to this function
will fire a preflash and record the required flash output (FE lock).
You can set the ISO speed by holding down <
0
> and turning the
<
6
> dial. If Auto ISO is set, manual ISO speed setting will take effect.
Auto ISO cannot be set. If you use this function in the <
a
> mode, you
can adjust the exposure with the ISO speed while maintaining the
current shutter speed and aperture.
During metering, you can set the ISO speed by turning the <
5
> dial.
If Auto ISO is set, manual ISO speed setting will take effect. Auto ISO
cannot be set. If you use this function in the <
a
> mode, you can adjust
the exposure with the ISO speed while maintaining the current shutter
speed and aperture.
In manual exposure <
a
>, you can set the shutter speed with the
<
6
> or <
5
> dial.
In manual exposure <
a
>, you can set the aperture with the <
6
> or
<
5
> dial.
: FE lock
: Set ISO speed (hold button, turn )
: Set ISO speed ( during metering)
: Shutter speed setting in M mode
: Aperture setting in M mode
COP
Y