First Look: Panasonic Lumix GH5

Image Assessment

Not only is the GH5’s LCD bigger (Figure 2, below), and the EVF higher resolution, but additional image assessment tools are built into the camera. Waveform and vectorscope are now standard. These “video only” tools are a huge step up from trying to rely on a histogram in the camera. I can imagine good external LCD monitors offering this feature will see a dip in sales.

Figure 2. The back panel of the GH5. Click the image to see it at full size.

The GH4 already had copious image controls (some say, perhaps even too many) but now, with waveform and vectorscopes in the camera, the effects of those controls can be accurately assessed. White balance can be ensured. Black levels and clipped highlights will be accurately represented by a scope, and not subject to the contrast and brightness of a monitor, or sun glare, or reflections.

Focus Tracking

When introducing the GH5, Panasonic went to great lengths to talk about focus points and their Depth from Defocus focus tracking for stills. It also applies to video. Tracking a moving subject becomes simple math for the processor. You can even preset up to three focus points and doing point-to-point focus pulls at various preset speeds, without overshooting or refocusing at the end. These can be executed wirelessly, so you can do a focus pull, or blow something out of focus deliberately, without shaking the camera.

While I haven't yet seen the demos proving it accurately tracks people walking to the camera like a camcorder, this is essentially what we're after here. The GH4 tried this, and it was just not quite there. Often overshooting, quickly (visibly) refocusing in the shot, the GH4 made continuous autofocus something you didn't want to use for video. The GH5 looks to change that.

Rolling Shutter

The GH4 already had one of the lowest rolling shutter skews in a DSLR. Compared to Sony, Canon, et al., the GH4 often took less than half the time to gather the image across the sensor, resulting in less “bendy” vertical lines and less “jell-o” in the image.

The GH5 improves this again and, side by side with the GH4, the improvement is clearly visible. While still not a "global shutter" like a CCD sensor, it's really getting close. Less distortion in the image is a welcome thing.

Color

Broadcast wants 10-bit 4:2:2 color space. Most DSLRs record only 8-bit 4:2:0 in a LongGOP video codec, like MPEG-4 or H.264. The GH5 will record 4Kp24/p30 with 10-bit 4:2:2 in a 150 Mbps stream. A firmware update coming this spring will add a 10-bit 4:2:2 1080p60 option. Arriving later this summer is the ability to utilize an All-Intra compression on 4K DCI 24p, UHD 24p, 30p capture at 400Mbps, and 1080p60 capture at 200Mbps, at 10-bit 4:2:2 color. This means that each frame is stored independently of the others. This makes it easier on the edit computer.

There have been numerous tests by pixel peepers in the the GH4 groups that have repeatedly come to the conclusion that 200 Mbps 1080p24/30 recorded in an All-Intra codec is not as clean as the LongGOP MP4 at 100 Mbps. The efficiency of the MPEG codec, as well as the inter-frame compression between frames means that even though the overall data rate is lower, the video stream is compressed much more efficiently and the LongGOP codec delivers a better image.

So if you have an older machine struggling with LongGOP 4K and constantly have to record in ProRes with an external recorder, or transcode your video to make your edit flow more smoothly, being able to shoot this way will help, but perhaps at a slight tax on your image quality.

VLOG will again be an optional purchase for the GH5, but this time, the camera can be loaded with up to four luts for previewing the shot with proper color while recording LOG footage in camera. There's even a 4K Hybrid Log Gamma for HDR video planned for Summer 2017, if that is something you need.

ISO

One constant complaint with Panasonic cameras was the inability to select Auto ISO in the manual movie mode, so you can select a wide aperture and 24 fps shutter, and let the camera ride the ISO for exposure. Plus, you can use exposure compensation to tell the camera whether you want it a little brighter or darker than the camera thinks it should be. Moreover, in full auto mode, you can now set the minimum shutter speed before the camera raises Auto ISO.