Yongnuo Speedlite YN968EX-RT for Cameras - Manual (Page 17)

If you need more flash output or wish to
perform more sophisticated lighting, you can
increase the number of slave units.
Simply set an additional slave unit to the
firing group (A, B or C) whose flash output you
want to increase. You can increase the
number of slave units up to 15 units in total( in
radio transmission).
For example, if you set a firing group with three slave units to ,the
three units are control led as a single firing group A with a large flash output.
Slave Group Control
Wireless Multi Flash Shooting
In wireless flash shooting you can create 1~5(up to three groups: A/B/C in
wireless shooting optical transmission) slave unit groups to achieve multi-
faceted flashing, and the master unit set up the flash ratio of TTL auto flash
shooting ,flash output,
multi flash or Gr mixed mode flash.
When the master unit set to ALL, the slave unit set to A / B / C group will fire in
the same mode and same flash output; when the master unit set to,
only set to A and B group the slave unit can be triggered; when the master
unit set to, only set to A,B,C group the slave unit can be triggered; If
you want to set the A,B,C,D,E group of slave unit can be triggered by the
master unit, please set the flash mode of master unit to Gr mode(The Gr
mode can only be selected in the wireless radio transmission shooting)
Wireless Flash Shooting
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