Canon EOS60D18135ISKIT User Manual (en)

 Using the Built-in Flash
If the [2 Auto Lighting Optimizer] (p.101) is not set to [Disable], the 
image may still look bright even if a darker flash exposure has been set.
If you set flash exposure compensation with both the camera and EX-
series Speedlite, the Speedlite’s flash exposure compensation setting 
will override the camera’s. If you have set flash exposure compensation 
with an EX-series Speedlite, any flash exposure compensation set with 
the camera will not take effect.
The exposure compensation amount will remain in effect even after you 
set the power switch to <2>.
By setting [8C.Fn IV -2: Assign SET button] to [4: sFlash exp. 
], you can just press <0> to display the flash exposure 
compensation setting screen.
The camera can also be used to set the EX-series Speedlite’s flash 
exposure compensation in the same way as with the Speedlite.