Here's the chart showing the results of this test (using the $3540 Xyla21 – 21 step Grayscale Combi-DX1):
|GH4 CineLike Dynamic Range Test - Assessed as 10.9 stops by Cinema5D|
The post describing these results gives us a few details about the methodology (e.g., the lens and ISO they used), but doesn't show waveforms or tell us which CineLike profile the testers used (this is important because CineLike V has less DR than CineLike D).
Fortunately, we can compare these results to other data-driven tests. The best I've seen is "Panasonic GH4: DR and Gamma, Timelapse, and More" from Adam Wilt writing for dvinfo.net.
Adam also used the Xyla 21 to test the GH4's Dynamic Range - but he tested it across various color and CineLike profiles. Here is his result for CineLike D:
|GH4 Dynamic Range Test - Assessed as 11+ stops by Adam Wilt at dvinfo|
Personally, I don't see a "videoish" look from my GH4 unless I want it. Neither do I see it from Phil Bloom's 4K Postcard from Phang Nha or Guillaume Le Berre's Kaydara.
That said, I really respect the effort the folks at Cinema5D put into this test, but in light of the significant difference with the dvinfo results, they might want to take another look at their conclusions.