User's Manual

If three slave units are all set to < > in terms of slave ID, these slave units will be controlled
as if they were one camera flash in slave group A.
5. M: Wireless Flash Shooting with Manual Flash

● When setting < RATIO A:B C >, group A, B and C will fire a flash synchronously; when
setting< RATIO A:B >, group C will not fire a flash.
● If shooting under the situation that group C is toward the main shooting subject, over
exposure might occurred.
● In some EOS film cameras that support E-TTL autoflash, you cannot perform multiple flash
wireless shooting with a flash ratio setting. 

● The flash ratio of 8:1 to 1:1 to 1:8 is equivalent to 3:1 to 1:1 to 1:3 (1/2 step increment).
● The details of the flash ratio settings are as follows.

Part