Canon Speedlite ST-E10 - Autoflash with Three Receiver Groups

Autoflash with Three Receiver Groups
Once flash groups A and B have been set up, you can add group C to fire with multiple flash
units. For an overview of flash control, see “Group Control.”
C is useful when you want lighting that eliminates the subject's background shadow.
1.
Set a flash unit as firing group C.
For instructions on configuring receiver settings, refer to the instruction
manual of the flash unit.
2.
Select [Flash group].
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