Other Settings - Canon EOS Rebel T4i 18-135mm IS STM Lens Kit Instruction Manual

Other Settings

Flash Exposure Compensation
When [Flash mode] is set to [E-TTL II], flash exposure compensation
can be set. The flash exposure compensation settings (see below)
which can be set will differ depending on the [Wireless func.] and
[Firing group] settings.
FE Lock
If [Flash mode] is set to [E-TTL II], you can press the <A> button to
perform FE lock.
234
[Flash exp. comp.]
The flash exposure compensation is
applied to the built-in flash and all
external Speedlites.
[2 exp. comp.]
The flash exposure compensation is
applied to the built-in flash.
[1 exp. comp.]
The flash exposure compensation is
applied to all external Speedlites.