Canon Macro Twin Light MT-26EX-RT Instruction Manual page 61

' Radio Transmission Wireless Multiple Flash Photography
Group Control
Slave A is controlled to fire with flash head A and slave B to fire with
flash head B as a group (as a single flash unit). Multiple units can be
used as slave C, D, and E. You can increase the number of slave units
up to 15 units.
Slave C Slave D Slave E
Firing group C
Firing group D Firing group E
Slave B
Slave A
Firing group B Firing group A
Flash head B Flash head A
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