I started again to play with the flash. I'm quite sure that to use the FL-300 in RC mode with the E-M10 you need to rise the pop-up flash. In this way everything works fine and both fire. Now I'd like to fire the external flash only. This because I want to learn with one flash only and also because it casts an ugly shadow with the 12-40. I was sure that I could go in the Flash menu and set the camera flash (bottom element) to off and be happy but this is not working now. Setting it off it still fires! I tried every combo with no luck... I found this answer in an old thread: RC Mode with FL-300R on E-PL5 a problem? but I really hope there is a better way then putting a hood on the pop-up to stop it. Any suggestion?