Canon Speedlite ST-E3-RT Mode D'emploi page 18

' Wireless Flash Shooting
Using a transmitter and a Canon Speedlite compatible with radio
transmission wireless shooting makes it easy to shoot with advanced
wireless multiple flash lighting, in the same way as normal E-TTL II/
E-TTL autoflash shooting.
The system is designed so that the settings of the transmitter attached
to the camera (master) are automatically reflected on the Speedlite that
is wirelessly controlled (slave). Therefore, you do not need to operate
the slave unit while shooting.
The basic relative positions and operating range are as shown in the
figure. You can then perform wireless E-TTL II/E-TTL autoflash
shooting just by setting the master unit to <a>.
Positioning and Operation Range
Autoflash Shooting Using One Slave Unit
x
Position the slave unit using the mini stand supplied with the flash.
Before shooting, perform a test flash (p.13) and test shooting.
The transmission distance may be shorter depending on the conditions
such as the positioning of slave units, the surrounding environment and
weather conditions.
16
M
(Example of wireless flash shooting)
(p.24)
Transmission distance
Approx. 30 m (98.4 ft.)