Canon Speedlite 430EXIII-RT Instruction Manual page 69

When you want to clear linked shooting, operate the Speedlites one by
one to change the setting to <P> in step 1.
You can use this function as a remote control for linked shooting without
attaching a Speedlite to a camera. Press <8> of the master unit and
select <L> to release all slave camera units.
During linked shooting, the time until auto power off takes effect is
approx. 5 min. for both the master and the slave units. Note that when
the interval of linked shooting is 5 min. or longer, set the "Auto power off"
to "OFF" on both the master and the slave units (C.Fn-01-1, p.83).
Linked Shooting with Radio Transmission
When changing the setting from
"slave unit" to "master unit" in step 2,
other Speedlites (or transmitters) that
were set as "master unit" until then
automatically switch to "slave unit".
Set up the slave camera units.
6
Set up all the slave camera units
within approximately 30 m/98.4 ft. of
the master camera unit.
Check that the <D> lamps of the
slave units are lit in green.
Take the picture.
7
Check that the <D> lamp of the
master unit is lit in green and take the
picture.
The slave camera units are released
linked with release of the master
camera unit.
After shooting with linked shooting,
the <D> lamps of the slave units
are briefly lit in orange.
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