Here is some nicely shot G3 footage, seems to have been shot in 720/50p mode. 720p on the G3 is roughly equivalent in resolution to 1080p on the Canon 5D Mark II.
The G3 looks to be a nice option for those who can’t afford or find a GH2. It also has 1080p, although it stores the 30/25p output of the sensor in an interlaced AVCHD format. No native 24p mode like the GH2. Is that a massive issue when the 720p mode is so good?
The G3’s sensor is 16MP, not quite as crowded as the GH2. It has very similar high ISO performance, in fact maybe a little better than the GH2. It has the same image processor too, so don’t rule out future hacks being able to get higher bitrates than 17Mbit enabling a 24/25p sensor mode on the G3.
17Mbit you might remember looked pretty horrible on the GH1, but that was at least 50% down to the poor encoder, which lacked b-frames. The G3 has the same encoding chip as the GH2 so 17Mbit is not much of an issue this time around.
The G3, then, runs the GH2 very close and if you are strapped for cash or can’t find a GH2 for sale anywhere and cannot wait to shoot, I’d recommend the G3 over the Canon 600D. The 5D Mark II of course is a different story, that full frame sensor still cannot be beat for fast wide lenses and shallow DOF, although the Micro Four Thirds sized sensor in the G3 is capable of razor thin shallow DOF at anything longer than 35mm and faster than F2. The 20mm F1.7 pancake is also quite nifty when it comes to shallow depth of field as well. It’s myth that you can’t get beautiful shallow DOF with a sensor half the size of full frame and a little smaller than S35mm / APS-C.
Just be aware though that if you want OIS and AF in video mode, those Lumix lenses aren’t cheap. But then at least you will have the option for it. A good choice for action / sports videos over the manual focus-only Canon video mode.
For professionals of course there are better options out there, not least of all the GH2 which punches well above it’s weight. It’s certainly worth the extra if you can find one and justify the addition of native 24p.