HOw to brighten my son's face ?

[anhyeuem]

Yes bro...
Iin flash mode, I can select few types of flash such as: auto, fill-in, slow, slow1
I have selected "fill-in" flash to be always fired but power of flash still not enought to power his face. My external Oly flash is set to TTL-auto.
My son stand 2-3m away from me.

just to try have you set flash to Full? If face is still dark then really is subject too far liao.