Imaging & Video Performance
The GH2 scores a very high resolution of 2000 x 2000LPH on our resolution chart, an impressive result not just from a Micro Four Thirds camera but from any DSLR camera. This rang true also out of the lab, with shots full of minute detail and beautiful pictures with punchy colors especially in the warmer tones. The quick contrast auto-focus Panasonic is known for its stills, shines on the GH2 as the subjects are focused on fast and accurately almost every time.
The other side of the coin for image quality is noise performance, and Panasonic's improved sensor delivers less image noise than its predecessor. Whereas older MFT cameras seem to have ISO1600 as an upper usable limit, the GH2 raises the bar to ISO3200, which can still be used with some noise reduction applied in post-production. Even though the GH2 lists ISO12800 as its highest setting, image noise starts to interfere with image detail noticeably beyond ISO3200. Although we still see some slight loss in detail starting from ISO1600, it's imminently better than the GH1's.
Video performance is integral to the GH2, since the GH1 has been widely adapted by videographers as a video camera, with some even hacking it to reach a higher bit-rate of 22Mbps. We found that shooting video in good light renders sharp details, with the beautiful depth of field you get from adjusting apertures. The auto-focus works beautifully, the lens is completely silent when focusing and doesn't detract from the sound. Sound pick-up is clear and the GH2 displays helpful sound level indicators when shooting.
The video seems to struggle with lots of tiny movement however, like tiny leaves rustling in the wind or ripples forming out of splashing water, which create compression artifacts. Shooting in low-light, image noise can be apparent, especially in skin tones – this is a camera which needs light or lenses which can shoot wide open. While the GH2 has doubled its sensor frame-rate output, it still limits shooting 1080/50i to a maximum bit-rate of 17Mbps. But it's added a new Cinema mode, which shoots 1080/24p at 24Mbps and gives videographers a 'filmic' look with higher bit-rates. You can also get uncompressed HD video by recording directly to an external device via HDMI.