Setting Up a Wireless Flash System
To set the 550EX as a slave unit, refer to page 53
in
the 550EX's
Instructions booklet.
ETTL
mZoom
2lfmm
c
Set the same channel No. as the
master unit.
Set the slave
10
to
C.
After
setting
up
the wireless flash
system,
position
slave C as
shown
in the left diagram.
• When indoors, position the slave unit
within 5 meters from the master unit.
When outdoors, position it within 3
meters. The slave unit should also be
within an aD-degree angle
in
front of
the master unit.
• Face the slave unit's transmission
sensor toward the master unit.
• Indoors, the transmission signals can
bounce off the walls so the slave unit's
positioning can be a little more flexible.
• Do not place any objects between the
master unit and slave unit which may
obstruct the wireless transmission.
Check
that
the master
unit's
pilot
lamp
is
lit
and
that
slave C
is
flash-ready.
~
When the slave unit is flash-ready, its
AF-assist light will blink.
43
