Canon EOS Rebel T6 Instruction Manual page 201

Clear flash settings

On the [External flash func. setting] screen, press the <B>
button to display the screen to clear the flash settings. When you
select [OK], the settings for the built-in flash and external
Speedlite will be cleared.
Setting the External Speedlite Custom Functions
The Custom Functions displayed under [External flash C.Fn setting]
vary depending on the Speedlite model.
Display the Custom Function.
1
Select [External flash C.Fn setting],

then press <0>.
Set the Custom Function.
2
Press the <Y> <Z> keys to select

the function number, then set the
function. The procedure is the same
as setting the camera's Custom
Functions (p.258).
To clear all the Custom Function

settings, select [Clear ext. flash C.Fn
set.] in step 1.
3 Setting the FlashN
201