Yongnuo YN650EX-RF Manual page 20

Wireless flash shooting
control unit. The method of directly setting the flash mode, flash output,
and flash coverage on this flash is the same as that of a normal
on-camera flash. To remotely set the parameters of the slave unit, you
only need to set the flash mode, flash output, and flash coverage of the
corresponding group on the master control unit and all the settings will
be synchronized to the group of slave unit flashes.
MASTER UNIT
•Wireless Flash Shooting Using 1 to 3 Slave Units
On the slave unit flash, short press [Gr] to enter the group setting
interface, turn the [dial] to set the slave unit to any group of A, B, and C.
On the master control unit, short press the function button [RATIO] to
turn on the flash ratio <RATIO ON>, and short press the [RATIO] again to
turn off the flash ratio <RATIO OFF>. Short press the [Gr] button to select
the control group, and turn the [Dial] to adjust the flash ratio and flash
output of the group flashes.
To make all the slave units in groups of A, B, and C flash with the same
output, please set to <RATIO OFF>.
If you need a higher flash output or better
lighting, you can increase the number of flash
units in one group of slave units.
For example: if the groups of 3 slave units are
set to <A>, they will be fired as a flash unit of
the slave unit group and controlled by the
master unit.
SLAVE UNIT
20