Canon EOS Rebel T5i 18-55mm IS STM Kit Instruction Manual page 239

Setting the Flash Output Manually for
Wireless Flash Shooting
When [Flash mode] is set to [Manual flash], flash exposure can be set
manually. The flash output settings ([1 flash output], [Group A
output], etc.) that can be set will differ depending on the [Wireless
func.] setting (see below).
[Wireless func.0]
[Firing group: 1All]: The manual
flash output setting will be applied to
all the external Speedlites.
[Firing group: 1 (A:B)]: You can set
the flash output separately for slave
groups A and B.
[Wireless func.0+3]
[Firing group: 1All and 2]: The
flash output can be set separately for
the external Speedlite(s) and built-in
flash.
[Firing group: 1 (A:B)2]: You can
set the flash output separately for
slave groups A and B. You can also
set the flash output for the built-in
flash.
Other Settings
239