Pansonic Lumix DMC-GH4 Is All About 4K Video

Panasonic's newest Micro Four Thirds mirrorless camera, the Lumix DMC-GH4, could have been called the GH4K: It's the first consumer-level interchangeable lens camera that we've seen that can capture 4K footage. Of course, it can also capture still images, 1080p video (at up to 96fps for slow-motion capture), and has a splash and dustproof design for all-weather shooting.

The GH4 looks a lot like the GH3($1,099.99 at Amazon) from a cosmetic standpoint. It's a mirrorless camera that's styled like a small SLR, complete with a modest hand grip, a faux pentaprism (it houses the pop-up flash), and an EVF that is centered behind the lens mount. But internally, almost everything has been updated.

The 16-megapixel image sensor is a new one, and it has an extra stop of ISO (up to 25600), and its readout is twice as fast as that of the GH3, which should minimize rolling shutter in video. The 3-inch vari-angle OLED display has increased to a 1,040k-dot resolution, and the OLED EVF is also sharper at 2,360k dots. The shutter is rated to 200,000 clicks (double the life of the GH3 shutter), and can fire at 1/8,000-second and sync with the flash at 1/250-second. The camera's burst rate is an impressive 12fps with locked focus, and up to 7fps with tracking.

Autofocus has also been slightly improved in terms of speed (it's rated at 0.07-second, versus 0.09-second for the GH3), but more interesting is the new focus technology that Panasonic has put into this camera. It's called Depth from Defocus, and it works in conjunction with traditional contrast detection to speed focus acquisition. It calls upon an internal database of lens characteristics to determine the distance at which the out-of-focus subject is from the camera and quickly racks the lens to that point, handing off to contrast detection only at the last step to verify focus. Panasonic showed some sample footage of the system in action; it's not dramatically faster than the GH3, but the subtle increase in speed was noticeable with side-by-side viewing.

While the improvements to the general camera body and still capture capabilities are there, the GH4's head-turning feature is video. It captures 4K footage at up to 30fps (24fps and 25fps are also available for a cinematic look), and it can store that footage at a 100Mbps bitrate using IPB compression in an MP4 or MOV container format. The standard aspect ratio for 4K footage is 16:9, but you can also set the camera to record wider footage (19:1) at 24fps.

Full HD (1080p) recording is also an option. The bitrate can go as high as 200Mbps here, but it can be dropped to 100Mbps or 50Mbps if top quality isn't required. Compression options include All-Intra and IPB, and you can select from frame rates of 59.94, 50, 29.97, 25, 24, or 23.98 frames per second. There's also a low bitrate option (28, 20, 10, or 4Mbps) for MP4 or MOV, and options for 28, 17, or 24Mbps for AVCHD Progressive or AVCHD; all of the low bitrate options use IPB compression.

Colors are sampled at 4:2:0 in 8-bit when recording to a memory card, but the camera can output a clean HDMI signal to a field recorder or monitor at 4:2:2. If you opt to record footage without a card in the camera—that is, to an external field recorder only—the output can be set to 4:2:2 at 10-bit depth.

There is a laundry list of features that are of interest to pro cinematographers. You can enable zebra patterns in the Live View feed, the GH4 can generate color bars and output an audio reference signal. It also supports time code (free running or during recording only), and offers synchro scan, luminance level adjustment, cinema gamma, master pedestal adjustment, and hue adjustment. There's an external dock available for broadcast use. It adds XLR audio input, audio level monitors and control, and features SDI connectors for 4:2:2 8/10-bit output with time code.

There's no word on the price or ship date for the GH4. Panasonic expects to announce that information in mid-March.