What I know........not much. FL-300R can be used as a slave and it's intensity varied. What I don't know.......quite a bit. If two FL-300R's are used, can their flash intensity be varied individually. How?...Guessing here, by assigning each to a group, how does the camera, E-M1, know the difference? If anyone has a linky explaining how to operate 'Olympus Wireless remote control Photography' it would be nice.