While I was in Dubai a couple of weeks ago at Gulf Photo Plus, I was able to play with a pre-production Panasonic GH5. I compared the GH5 to the Nikon D750 (our current video camera of choice) and the Sony a7S II.
The GH5 can shoot in a range of different sizes, bitrates, and color profiles. I did test them all one by one but I purposefully left most of that out of this video simply because I'm not sure much can be gained form that footage, especially once it's compressed with Premiere and then again with YouTube.
The 1080p footage out of the camera looks significantly better than the 1080 footage out of our D750. The GH4 was plagued with notoriously bad 1080 output which caused it users to shoot in 4K and downsample to get sharper 1080 footage. This is no longer necessary as 1080 footage and 4K footage downsampled to 1080 looks almost identical.
The 4K footage out of the camera is sharp and looks very simpler to the 4K footage out of the a7S II. The color profiles do give you some options when it comes to the way your footage looks but for all of the tests in our video, the camera was set to "standard."
8 bit vs 10 bit
I was really excited to hear that the GH5 is now capable of shooting in 4K at 150 Mbps 10 bit. This is supposed to add a ton more color and detail to the video, especially noticeable in gradients. Sadly, in my tests I couldn't see any difference at all between 8 and 10 bit. Even when I purposefully underexposed a shot and brought it up in post, both shots look almost identical. Perhaps I wasn't shooting the best subject to highlight this feature.
The digital zoom on the GH5 is worthless for when shooting in 4K. Instead of "cropping in" on the sensor, it seems to just be cropping the footage. The footage looks the exact same if you digitally crop in camera or "zoom in" to the 4K footage in Premiere afterwards. The digital zoom does work if you are shooting in 1080 but it produces footage that looks identical to shooting in 4K and then zooming in once you get back into post as well.
We didn't test the built in mic on the GH5 because we don't ever use the built-in mic on our cameras. Instead we tested the "audio in" jack on the camera and used a wireless lav system. We wanted to test that we could monitor audio easily with headphones, and also test the final quality of sound recorded by the camera. The GH5, D750, and a7S II were all able to record audio that sounded pretty similar but the GH5 does have a limiter/compressor that can help tame extreme shifts in volume. We didn't test this feature extensively but it does seem like a very useful feature, especially if your camera is quick to clip audio like the D750 is.
The Panasonic GH5 has pretty impressive ISO performance, especially for its size. I would say that it performed very similarly to the Nikon D750 with footage really starting to fall apart after ISO 6400. When compared with the Sony a7S II, however, both of these cameras simply can't compete. They both seem to be about 3 stops behind.
If you find yourself shooting in dark locations often, the Sony is certainly the way to go.
The stabilization in the GH5 is the best I have ever used. When you turn on the stabilization in the lens, body, and the "e-stabilizer," the camera almost becomes it's own gimbal. Walking around certainly isn't as smooth as using a gimbal, but if you're standing still, it is now possible to get tripod-like stabilization without much effort.
We've used a number of Panasonic cameras and they all have a similar time-lapse feature that allows the camera to take pictures (with a slow shutter speed) and then when finished, you can tell it to create a 4K time-lapse video from those still images. The camera then saves the images and the videos separately. This feature has completely changed the way we shoot time-lapses and makes the entire processes almost completely automated. Shooting in both full manual or allowing the camera to choose its own shutter speed will produce flawless time-lapses in camera that do not have flicker. All Panasonic cameras, not just the GH5, have this feature and if you're tired of manually building time-lapses in post, I highly suggest giving it a try.
Other Key Features
This camera has a great touch screen that can flip out to the side and rotate in any direction. It has timecode that can be used to sync multiple cameras using an iPhone app. I'm also really excited to play with the 180fps 1080 slow motion. The biggest upgrade for us, and the feature that every DSLR should have by now, is unlimited shooting times. I'm so sick of having to start and stop our cameras every 20 minutes and this feature alone was enough for me to choose the GH5 over the Sony a7S II.
The GH5 is a pretty impressive video camera but it isn't perfect. I do wish that the ISO performance was a little bit better. I'm not sure if the camera really needs to be 20MP as I imagine most people who buy it will be using it for video. Perhaps if it was only 8MP (the exact size of 4K video) it would be a little better in low light. And if they are going to make the sensor 20MP I would have really appreciated a legitimate "digital zoom" that was actually useful.
One major benefit to the smaller sensor size though, seems to be the inclusion of e-stabilization, which simply does not work on full camera sensors at this time due to rolling shutter. We have to take the good with the bad but in the case of the GH5 it's mostly good. It's only real competitor seems to be the a7S II and if its successor, the a7S III, finally removes the record limit, can overcome all overheating issues, plus improve stabilization, the GH5 may no longer my first choice but as things stand today, I'm excited to make the GH5 our standard video camera here at Fstoppers. I've preordered three of these camera systems and I will probably order three more once I can do a full review. The GH5 should officially ship out by March 30, 2017.