Canon EOS 7D Instruction Manual page 125

[1 (A:B C)] Multiple slave units in multiple groups
C
Indoors
A
Outdoors
If [Firing group] is set to [1 (A:B)], group C will not fire.
If group C is pointed toward the main subject, overexposure may result.
Approx. 10m
(32.8ft.)
Approx. 7m
(23.0ft.)
Approx.
o
80
5m (16.4ft.)
1
Set [Firing group] to [1 (A:B C)].
2
Set the desired flash ratio and
shoot.
This is a variant of the [1
(A:B)] setup on the preceding
page. This setup has group C
eliminate the shadows
Approx.
created by groups A and B.
B
7m
Refer to your Speedlite's
(23.0ft.)
instruction manual to set the
slave ID of the three slave units
to A (Group A), B (Group B),
and C (Group C) and position
them as shown in the
illustration.
Select [A:B fire ratio] and set the
flash ratio.
Set flash exposure compensation for
group C as necessary.
Using Wireless FlashN
125