I've got an EP3 with a pop-up flash. I've got an FL-300R and am getting an FL-600R for my birthday. Can I set the strength of the remote flash independently from my on-board or pop-up flash? I'd like to really weaken the pop-up flash so that it is only adding a weak fill, while have the remote flash trigger more strongly. Can I do that, and is it different whether using the 300 or 600? Thanks. I'm still a newbie with Flash, but am trying to learn.