Canon ST-E3-RT-V2 Manual page 34

a: Wireless Multiple Flash Shooting with Flash Ratio
Receiver Group Control
Firing group A
Gr = A Gr = A
For example, if you set a firing group with three receiver units to <4>,
the three units are controlled as a single firing group A with a large flash
output.
To fire the three firing groups A, B and C at the same time, set

<^>. With the <%> setting, firing group C does
not fire.
If you shoot with firing group C pointing directly toward the main subject,

overexposure may result.
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-

stop increments) when converted to number of stops.
The details of the flash ratio settings are as follows.

34
3
Set flash exposure compensation
as required.




If you need more flash output or wish to
perform more sophisticated lighting, you
can increase the number of receiver
units. Simply set an additional receiver
unit to the firing group (A, B or C) whose
Gr = A
flash output you want to increase. You
can increase the number of receiver
units up to 15 units in total.
Press function button 3 <F>,
turn <9> and select <6>.
Press function button 3 <B>.
Turn <9> to set the flash exposure
compensation amount, and press the
<8> button.
Press function button 4 <?> to
return to the shooting-ready state.