Canon Speedlite EL-100 - Manual (Page 50)

50
Wireless Multiple-Flash Photography with Flash Ratio
Setting up receivers
2
Set the flash group.
z
Set the Mode dial of each receiver to
the group in which it will fire (<
4
>
or <
5
>).
Autoflash with Three Receiver Groups
B
A
C
Once flash groups A and B have
been set up, you can add group C.
Group C is effective in eliminating
shadows in the background behind
subjects.
Basic settings are the same as
for “Autoflash with Two Receiver
Groups” (p.49).