Chris, you might want to consider the Panasonic Lumic G X Vario 14-42mm instead of the Olympus 12-50mm. The Panasonic has Power O.I.S, which is important for video. The Olympus won't have any sort of Image Stabilization on the GH4. Go over to the video section of the forum and Peter from Australia is some info and video showing the use of the 14-42mm. You can use diopter on it (+10 is recommended). For wide angle, you can find a wet lens that work for it.
I just get my GH4 and the 14-42mm lens today, but I haven't get the housing yet. I plan on using my Opteka .45x 67mm lens on it for wide angle.
- ChrigelKarrer likes this