Canon EOS 7D Mark II (G) Instruction Manual page 268

3 Setting the FlashN
Wireless functions / Flash ratio control
Flash zoom (Flash coverage)
268
Wireless (multiple) flash shooting is
possible with radio or optical
transmission.
For details on wireless flash, refer to the
instruction manual of a Speedlite
compatible with the wireless flash
shooting.
With a macro flash (MR-14EX II, etc.)
compatible with external flash function
settings, you can set the flash ratio
between flash tubes or flash heads A
and B, or use wireless flash with slave
units.
For details on flash ratio control, refer to
the macro flash's instruction manual.
With Speedlites having a zooming flash
head, you can set the flash coverage.
Normally, set this to [AUTO] so that the
camera will automatically set the flash
coverage to match the lens focal length.