Canon EOS Rebel T4i 18-135mm IS STM Lens Kit Instruction Manual page 218

3 Setting the FlashN
Setting the External Speedlite Custom Functions
The Custom Functions displayed under [External flash C.Fn setting]
will vary depending on the Speedlite model.
Clear the Settings
218
Display the Custom Function.
1
With the camera ready to shoot with
an external Speedlite, select
[External flash C.Fn setting], then
press <0>.
Set the Custom Function.
2
Press the <U> key to select the
function number, then set the
function. The procedure is the same
as setting the camera's Custom
Functions (p.292).
Select [Clear settings].
1
Under the [z1: Flash control] tab,
select [Clear settings], then press
<0>.
Select the settings to be cleared.
2
Select [Clear built-in flash set.],
[Clear external flash set.], or [Clear
ext. flash C.Fn set.], then press
<0>.
When you select [OK], the respective
flash settings will be cleared.