Canon Speedlite 600 EX-RT User Manual (en, zh)

You can directly operate the slave unit to manually set the manual flash 
or stroboscopic flash. This function is called individual slave. This is 
convenient when, for example, you use the Speedlite Transmitter ST-E2 
(sold separately) to perform wireless manual flash or stroboscopic flash.
Set the slave unit 
Set the individual slave.
Press the <E> button on the slave 
unit continuously until 
<(> is displayed.
The flash mode is set to <q>.
Set the manual flash output (p.31).
Press the <E> button and set to 
Set the stroboscopic flash settings 
Press the <E> button again to 
return to the normal slave status.
Manual Flash/Stroboscopic Flash Setting on a Slave Unit
Manual Flash
Stroboscopic Flash
The flash frequency for stroboscopic flash during optical wireless 
transmission shooting can be set from 1 Hz to 199 Hz (settings from 250 Hz 
to 500 Hz are not available).
A slave unit set as an individual slave does not reflect the master unit’s flash 
mode. It fires in the flash mode set on the individual slave.