Attila Bakos

Ah I see. To create Fujifilm Film Simulation LUTs I need to have the camera for 1-2 weeks, and I don't know a single person in my area who owns it. The other thing is that it takes quite a lot of time for me to create these packs so I mainly go for cameras with large user base. In this regard I'm not sure about the F3.

New ACES IDT packs are released:
Leica L-Log/BT.2020 Fujifilm F-Log2/F-Gamut You can get them from here: https://colorizer.net/dev/index.php?op=aces
The Fuji one I did almost blindly, I couldn't get my hands on original F-Log2 clips yet, but since the data sheet is already out I created this package anyway. I used youtube framegrabs for verification and I can already see that if you bring F-Log and F-Log2 to the same contrast, the latter has more saturation, especially in the yellow-red area. And greens are a bit more yellow, foliage seems to be warmer.

But that's already there in Resolve:

 

New ACES IDT packs are released:
Leica L-Log/BT.2020 Fujifilm F-Log2/F-Gamut You can get them from here: https://colorizer.net/dev/index.php?op=aces
The Fuji one I did almost blindly, I couldn't get my hands on original F-Log2 clips yet, but since the data sheet is already out I created this package anyway. I used youtube framegrabs for verification and I can already see that if you bring F-Log and F-Log2 to the same contrast, the latter has more saturation, especially in the yellow-red area. And greens are a bit more yellow, foliage seems to be warmer.

Hello,
This is the official topic for all Colorizer products.
My main focus is bringing high-precision Fujifilm Film Simulation LUTs to multiple cameras.
The following formats are supported at the moment, click the links for videos and details:
Fujifilm X-T3/X-T4 F-Log
Sony S-Log2/S-Gamut3.cine
Panasonic V-Log L & HLG
I also sell ACES IDTs for cameras that are not natively supported by Davinci Resolve:
- Fujifilm F-Log/F-Gamut
- Nikon N-Log/BT.2020
- Sony S-Log2/S-Gamut3.cine
- Z Cam ZLog2
- GoPro Protune
These packs include a lot of 3D LUTs simulating the ACES Rec.709 look, so it can be valuable for Premiere users as well.
I also have Technical fixes for common color shift issues caused by bad interpretation of certain clips in Premiere. I strongly suggest you check this out if you're a Fujifilm user.
As a bonus I created a bunch of free online tools for creating and modifying 3D LUTs, so if you're into this kind of stuff, visit http://colorizer.net.
Thank you for your attention,
Attila

New ACES IDT packs are released:
Leica L-Log/BT.2020 Fujifilm F-Log2/F-Gamut You can get them from here: https://colorizer.net/dev/index.php?op=aces
The Fuji one I did almost blindly, I couldn't get my hands on original F-Log2 clips yet, but since the data sheet is already out I created this package anyway. I used youtube framegrabs for verification and I can already see that if you bring F-Log and F-Log2 to the same contrast, the latter has more saturation, especially in the yellow-red area. And greens are a bit more yellow, foliage seems to be warmer.

And nobody here said it's not, yourself included. A little explanation would have helped, as always.

@tupp nice analysis, I really have to take a look at Darktable again sometime 🙂

It appears that Fuji is essentially using wavelet/frequency-separation in the chroma channels to isolate and blur certain areas.
I tried that scenario on your "5D3 Raw" chroma channel image (captured from your Resolve viewer with MPV), using the Darktable Contrast Equalizer module:

I didn't get it to look exactly the same as the X-T3 chroma channel image, but the "blotchiness" achieved is fairly similar.
Here is the curve used in the Contrast Equalizer module:

The scale from left to right delineates coarse patterns to fine patterns in the image.  The mostly flat line going through the center is the sharpness curve, and the "S-shaped" line is the smoothing curve.
Many use the Contrast Equalizer for denoising and sharpening, but in such applications, the smoothing curve always lies below the sharpening curve.  Nobody ever inverts the two curves as shown on the right side of the graph.
I also used the Soften module with a parametric mask to add extra blur to the brighter areas, because the Contrast Equalizer did not provide enough blur.
The excessive chroma blurring from the X-T3 way too much for demosaicing, and it's extreme overkill for noise reduction.  There also seems to a bit of coarse pixelation revealed when you zoom-in in your video, so perhaps Fuji is additionally doing a pseudo chroma subsampling.
Whatever Fuji is doing (and for whatever reason), the process is effectively reducing the color resolution, which results in a perceptible loss of color depth.
 
The X-T3 is excessively lowering the effective chroma resolution with blurring, which dramatically reduces the color depth.
The raw files don't have that problem, because their resolution is not being reduced.
The "processing" is likely something similar to what I have shown above, and it essentially is reducing the color resolution, hence the lower color depth.  Remember, with digital imaging:
COLOR DEPTH = RESOLUTION x BIT DEPTH
By the way, when are you going to take back that lie you told about me?

I used ffmpeg first to extract the chroma channels into grayscale videos and I used that to validate the results of my plugin. They were identical so it's safe to say that it's not an NLE/GPU decoder issue.

There must be some clever algorithm behind this as it seems to have proper 1080p resolution around well defined edges, but everywhere else it's clearly less than that.

Not at all! Do you plan to include info from the Petapixel article as well, or link that article? With the information there my video makes more sense.

You're not alone with that thought, which is why many including myself left the system. The option to turn off chroma NR should definitely be there, especially since unlike in RAW stills there is no getting around it in video.. 
Like I've been repeating, this an infamous issue in the Fuji community. It's kind of a taboo subject though. Whenever it gets brought up,  people usually dismiss it by saying shoot RAW. I still think its quite jarring as the jpg film simulations are a huge part of the Fuji-X philosophy. 
Again, for videographers there is simply no workaround this issue, hence this topic should really be brought to Fuji's attention imo.
 

Great... I'd rather have an OLPF and slightly less overall resolution than slightly more luma and noticeably less chroma. Or at least they could allow us to modify/switch off the chroma NR.

Unfortunately I won't have the time to test this anytime soon, and I'm not sure it's worth it. The Petapixel artice is absolutely correct about the interpolation issues of the X-Trans pattern, technically there is more guesswork there, and the camera won't have the processing power for a sophisticated demosaicing algo. It's pretty slow even on PC. So I'm sure that the in-camera demosaicing leaves some color artifacts that Fujifilm chose to hide with chroma NR, but they might have gone overkill with that. And I'm surprised that I don't see an improvement on the GFX bodies.

A last sample, this is from the GFX100s, 4K, 400Mbps, 8bit H.264. It's not F-Log, possibly Provia, so it's chroma channels are supposed to be slightly better compared to F-Log: https://drive.google.com/file/d/1F4W_DYYkYlQIV49lakIGuz1L4xnB3oNm/view?usp=sharing
From top to bottom: Original, Cb (with added contrast), Cr (with added contrast)
I post this because there are some trees in the background.
The theory about this being an X-Trans only issue sounds fine, I might even believe it, but then all the clips that I found from GFX bodies so far tell a different story.

I found something strange when I was looking at the chromaticity channels of Fujifilm video files and did some search online, and to my surprise noone is talking about this, so I decided to make a video about it. If you're a Fuji user, you might be interested.
 

I found something strange when I was looking at the chromaticity channels of Fujifilm video files and did some search online, and to my surprise noone is talking about this, so I decided to make a video about it. If you're a Fuji user, you might be interested.
 

People like to mention smooth skin tones when it comes to Fuji JPEGs. I prefer to have all the details and do my own smoothing, but for many people this phenomenon is actually a plus 🙂
I was searching online a lot after I discovered this, I couldn't believe that no one is talking about this. I think I only found one old topic from dpreview where someone mentioned chroma smoothing happening in Fuji JPEGs, but I can't find it now. So we are quite alone here 😄

Even if they blur the crap out of it, they do it in a smart way, I'm not sure if it's visible in the video but the houses and vehicles have good chroma details in the Fuji, it's the foliage that suffers a lot, where you're not expecting too much color difference.

I found something strange when I was looking at the chromaticity channels of Fujifilm video files and did some search online, and to my surprise noone is talking about this, so I decided to make a video about it. If you're a Fuji user, you might be interested.
 

I found something strange when I was looking at the chromaticity channels of Fujifilm video files and did some search online, and to my surprise noone is talking about this, so I decided to make a video about it. If you're a Fuji user, you might be interested.
 

Hello,
This is the official topic for all Colorizer products.
My main focus is bringing high-precision Fujifilm Film Simulation LUTs to multiple cameras.
The following formats are supported at the moment, click the links for videos and details:
Fujifilm X-T3/X-T4 F-Log
Sony S-Log2/S-Gamut3.cine
Panasonic V-Log L & HLG
I also sell ACES IDTs for cameras that are not natively supported by Davinci Resolve:
- Fujifilm F-Log/F-Gamut
- Nikon N-Log/BT.2020
- Sony S-Log2/S-Gamut3.cine
- Z Cam ZLog2
- GoPro Protune
These packs include a lot of 3D LUTs simulating the ACES Rec.709 look, so it can be valuable for Premiere users as well.
I also have Technical fixes for common color shift issues caused by bad interpretation of certain clips in Premiere. I strongly suggest you check this out if you're a Fujifilm user.
As a bonus I created a bunch of free online tools for creating and modifying 3D LUTs, so if you're into this kind of stuff, visit http://colorizer.net.
Thank you for your attention,
Attila

Hello,
This is the official topic for all Colorizer products.
My main focus is bringing high-precision Fujifilm Film Simulation LUTs to multiple cameras.
The following formats are supported at the moment, click the links for videos and details:
Fujifilm X-T3/X-T4 F-Log
Sony S-Log2/S-Gamut3.cine
Panasonic V-Log L & HLG
I also sell ACES IDTs for cameras that are not natively supported by Davinci Resolve:
- Fujifilm F-Log/F-Gamut
- Nikon N-Log/BT.2020
- Sony S-Log2/S-Gamut3.cine
- Z Cam ZLog2
- GoPro Protune
These packs include a lot of 3D LUTs simulating the ACES Rec.709 look, so it can be valuable for Premiere users as well.
I also have Technical fixes for common color shift issues caused by bad interpretation of certain clips in Premiere. I strongly suggest you check this out if you're a Fujifilm user.
As a bonus I created a bunch of free online tools for creating and modifying 3D LUTs, so if you're into this kind of stuff, visit http://colorizer.net.
Thank you for your attention,
Attila

Hello,
This is the official topic for all Colorizer products.
My main focus is bringing high-precision Fujifilm Film Simulation LUTs to multiple cameras.
The following formats are supported at the moment, click the links for videos and details:
Fujifilm X-T3/X-T4 F-Log
Sony S-Log2/S-Gamut3.cine
Panasonic V-Log L & HLG
I also sell ACES IDTs for cameras that are not natively supported by Davinci Resolve:
- Fujifilm F-Log/F-Gamut
- Nikon N-Log/BT.2020
- Sony S-Log2/S-Gamut3.cine
- Z Cam ZLog2
- GoPro Protune
These packs include a lot of 3D LUTs simulating the ACES Rec.709 look, so it can be valuable for Premiere users as well.
I also have Technical fixes for common color shift issues caused by bad interpretation of certain clips in Premiere. I strongly suggest you check this out if you're a Fujifilm user.
As a bonus I created a bunch of free online tools for creating and modifying 3D LUTs, so if you're into this kind of stuff, visit http://colorizer.net.
Thank you for your attention,
Attila