Attila Bakos

Ah yes you are probably right 🙂

Yes the log profiles are worse. Btw when you're testing chroma components in Fuji files, make sure to skip the first few frames, those are worse than the rest.

It's not the red channel that's blurred but the chroma components in the YCbCr format, that is Cb, and Cr. Both Cb and Cr are blurred the same way, but I used Cr for demonstration as it shows the issue a bit better. Btw Cr is red minus luma, so you are not that far from the truth 🙂

Forgot to mention that in this test in hybrid mode the decoding was done by the iGPU and the encoding was done by the dedicated GPU (as I encoded to 4:2:0), so they can really work together.

No, I'm referring to NVIDIA/AMD. I just did a test for you. I have a Lenovo Legion 5i Pro laptop with an i7-12700h CPU and a 3070Ti GPU. I loaded a 2160p 4:2:2 HEVC F-Log clip to Resolve, added a LUT and some tweaking. With hybrid mode enabled (that is Resolve can use both internal GPU and the dedicated one), I get smooth 25fps playback with low CPU usage and rendered out the clip with the H.265 Master preset in 18 seconds. Now if I switch to dedicated GPU only mode, I get 21-23 fps playback and high CPU usage and the clip rendered out in 41 seconds. So basically with 10th or higher gen Intel CPU I get 4:2:2 support in addition to what the GPU already offers, no need for a Mac (for this).

But what if you have an Intel processor with 4:2:2 decoding support and a dedicated GPU? I was under the impression that they can work together.

That's true, however Intel QuickSync supports hw encoding/decoding of 4:2:2 HEVC since Gen10. Better than nothing 🙂

How do you import the video into GIMP? We can move to private message.

No I'm not selling it yet, but I validated my results with ffmpeg as it can extract the chroma channels as grayscale and I can safely say that my results are correct. How do you extract the channels in gimp?

Here is a short demonstration of the Cr channels: https://drive.google.com/file/d/1veiqGodXKxerdNF_ksqLlAnFWbGQUtEe/view?usp=sharing 8bit is rubbish, never ever use it. 10bit is somewhat better than on the X-T3/4, but the chroma smoothing is still there, ProRes doesn't seem to help either. Interestingly the X-H2s seems to have more smoothing than the X-H2. As much as I love Fuji for stills, I think I'll stick to other brands for video as I'm very sensitive for this kind of stuff, but for 99.9% of Fuji video shooters this is still a non-issue I guess.

Thank you for all the clips, I hope I can take a look at them this evening.

It's not important to shoot at the same time for this test, if the light is more or less the same then it's fine. When you shoot with other cameras, please use a format that's encoded in YCbCr (h.264, h.265, ProRes for example), as raw won't have this problem.

Please shoot something with lots of fine detail and varying colors at infinity focus (trees with autumn colors are the best, check my youtube video I posted in this topic), both h.265 and ProRes. When it comes to h.265, the higher bitrate the better, and ProRes should be 422. UHD or higher resolution is fine. When comparing both cameras, please use the same scene with the same settings. F-Log and/or F-Log2 please. I know I ask a lot, but if you have other cameras as well, Canon/Sony/Panasonic, it would be nice to see them as well. The issue might not be obvious until you start to compare it with other cameras.

Finally some noise in the Cr: https://www.dropbox.com/s/mesy1evzib28hb2/DSCF0234_Cr.mov?dl=1 Noise is good in this case. When you have a chance to do more, please use 422 instead of LT, I was told that the difference in quality was noticeable in the X-H2(s), and minimal between 422 and HQ.

I downloaded the 8K video sample from the bottom of this article: https://www.photographyblog.com/previews/fujifilm_x_h2_photos It's 7680x4320 10bit 4:2:0 H.265 29.97fps, but only 100Mbps. 4:2:0 means that the chroma resolution should be 3840x2160. So I put the clip on a 3840x2160 timeline, and on the right side you see the Cr channel with added contrast for better visibility: https://www.dropbox.com/s/e04fm6oc5ac9qbz/X-H2_chroma.mov?dl=1 I'll let you judge this, but I don't like what I see. Higher bitrate might help, or ProRes as well, but the chroma processing is still here with us 🙂 And this is not even F-Log where the issue was more prominent in the past.