After years surfing this forum, I've finally joined the Panasonic club (sorry Nikon). I picked up the camera last week and haven't dived into customizing the function buttons yet - I'd like to know how other GH4 owners mapped them for some ideas.
Since after so long, I felt I should answer your post!
I My mapping, going from top to bottom:
1. Electronic Tele-converter.
2. Motion picture quality.
3. Variable Frame Rate.
4. Metering mode.
5.Synchro Scan.
I use synchro scan a lot to sync up with monitors and other light sources. Just remember, that you can have separate settings for each custom function, which really opens up the customizability.
