Canon 580EXII Instruction Manual page 38

Fully Automatic Wireless Flash
This method has all the Speedlites fire at the same flash output with E-
TTL II autoflash controlling the total flash output.
ETTL
mJZoom
2'-1mm
Set the camera-attached 580EX II
as the master unit.
ETTL
mJZoom
2'-1mm
Set the other 580EX II
Speedlites(s) as the wireless
slave unit(s).
ETTL
mJZoom
2'-1mm
~~
~~A
Check the communication
channel.
If the master unit and slave unit(s) are
set to a different channel, set them all
to the same channel (p.40).
Position the camera and
Speedlites.
Position the Speed lites within the
range shown on the next page.
Set the master unit's flash mode
to
<ETTL>.
For shooting,
<ETTl>
will also be
set automatically for the slave unit(s).
Check that the flash is ready.
When the slave unit(s) is ready to fire,
the AF-assist beam will blink at 1-sec.
intervals.
37