It should be pointed out that Panasonic has gotten almost everything right with the GH3. They have addressed more user suggestions in one version update than most companies do in three. Not only have they given higher bitrate recording modes, but they also seemed to have increased dynamic range (even if only slightly). The other big feature that wasn't given as much attention is the ability to record the uncompressed signal from the HDMI. There have been rumblings about the color space coming from the HDMI, and it had been noted in many places that the output was only 8-bit 4:2:0. Since the camera isn't final, and not all Panasonic employees were familiar with the finer details, I had initially been hesitant about posting the information. Now EOSHD has an interview with a senior engineer at Panasonic about the issue.
Yoshiyuki Inoue, a senior engineering planner at Panasonic, said this in EOSHD's interview about the GH3:
Ah, the format after processing for HDMI – has no compression. It is 4-2-0...This depends on the system internal structure. This one is optimised for the still picture quality also.