I've owned all 3 cameras and the GH3 was a huge improvement over the GH2 for still image quality (and a nice bump for video as well). Raw recovery and push was much better than the GH2. The GH4 is a slight improvement over the GH3 for still image quality and a gigantic leap for video. The biggest improvement for stills over the GH3 is the autofocus capability, which is incredibility good. If you're an action shooter, it will improve the percentage of "keepers" that you get by a large margin. I've been shooting a lot with the Oly 12-40mm and that lens tracks very well without even taking advantage of the DFD tech.

I'm a GH3 owner who's been a stills portrait pro for close to 40 years, shot Mamiya RB67 for near 30 years, ran my own custom & production lab for prints to 40" long for a decade or so while working the portrait studio. My main "gun" for the last 4 years has been a D3 Nikon ... that thing at 40" pretty well matched 6x7cm neg quality, but at ISO's that were way beyond dreaming with the RB.

I'd hoped the GH3 stills would be close enough to say an improvement on my old D200 if not a full equivalent of the D3. Well ... we can use GH3 stills for say wedding candids or commercial portrait headshots that are going to be on the web at smallish size. In a pinch for something 8x10 inch or slightly bigger. There's a ... blockiness? ... chunkiness? ... to the images in say close looking at generally smooth surfaces like cheeks.

I've seen prints from GH4's that are decidedly less blocky/chunky, if there's still a hint at times. And there's none of the plasticine-skin look to the GH4. I could use one for a quite a bit wider range than my GH3 without problem. Wouldn't replace the wife's D600 for stills shooting, but ... for printing 14 inch and under on the long side, should be fine. (And I'm a picky sot ... )

Neil

Judging from the samples here:

http://www.photographyblog.com/reviews/panasonic_lumix_dmc_gh2_review/ http://www.photographyblog.com/reviews/panasonic_lumix_dmc_gh4_review/

...it looks like shadow detail has improved nicely, with a bit of highlight improvement, too. I had a GH2 (bought for video), and pretty much cringed when I used it for photos, every time. Compared to my old Nikon D90 (2 years older), its colors were horrible, and lifting shadows even at base ISO meant a large increase in noise and chroma splotches. The GH4 mostly gets rid of that, though there's no increase in sharpness to be seen. Sony and Fuji still have vastly superior sensors (especially Sony) than Panasonic, even on their low end mirrorless. Olympus seems to one-up Panasonic on mostly highlight recovery, reaching Sony sensor levels. Check the site above for lots of RAW samples of just about any camera out there.