Attila Bakos

1 hour ago, kye said:

Yeah, and compare it to the other two.  If it has huge amount of noise because of the X-Trans sensor then we'll know, and if it doesn't, we'll know the chroma processing isn't for 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.

1 hour ago, kye said:

Considering you have access to the camera...

I have access to an X-T3, EOS R, and 5D3. The GFX samples I found online. Did you mean to test with the X-T3?

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.

If it's the X-Trans CFA, what's the explanation for the GFX results I posted earlier? 

48 minutes ago, Andrew Reid said:

Are we sure it isn't a GPU decoder / NLE problem and it is definitely the camera?

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.

Another samples, this time from the GFX100, keep in mind that this is 8bit: https://drive.google.com/file/d/1fyCiDFhbkskhjxz2miFgLXn523uP80ns/view?usp=sharing

Sequence is the same as before: original, Y, Cb (with added contrast), Cr (with added contrast)

This might be the worst I've seen so far.

I don't know guys... just found two GFX100s F-Log clips here (200Mbps 10bit HEVC): https://drive.google.com/drive/folders/1UpKhgQpv8D6pEICjEBvLuAaSTSEvQaHX

And here is the result (download please): https://drive.google.com/file/d/1vjFxXTTaqftD8E8GN1vrT5ZTPkaUb6Nq/view?usp=sharing

The sequence is the following: original, Y, Cb (with added contrast), Cr (with added contrast)

Would be nice to see something more colorful, but I already don't know how this is any better from what we have seen from the X-T3 so far.

Alright, we agree then 🙂 Now I would LOVE to see an F-Log sample coming from a GFX body.

11 minutes ago, Django said:

@Attila Bakos Not really necessary. This article breaks it down, it has to do with Xtrans & Fuji’s heavy chroma NR jpeg engine :

https://petapixel.com/2017/01/27/x-trans-promise-problem/

But this proves my point. It's the chroma NR. The reason they apply it might be related to X-Trans but that's all, X-Trans alone won't cause what you see in my video. Easy to prove, I might do it later when I get home.

1 hour ago, androidlad said:

Nice video, inquisitive as always.

This is mostly due to the nature of X-Trans, there are far more green photosites than red and blue, compared to traditional Bayer sensors, hence the less detailed Cr channel. The benefit is that it naturally reduces moire and it has a bit cleaner luminance detail (Y channel).

You won't notice this on videos shot on Fuji GFX cameras which use Bayer sensor.

I believe this has nothing to do with demosaicing, all the color information that's missing from the videos/jpegs are there in the x-trans raw files. I can show it tomorrow if necessary.

Edit: looking at Django's comment it's necessary 🙂

42 minutes ago, kye said:

There are all sorts of image processing algorithms they could be using.  Whatever it is though, it's not high quality!

It's such a pity as Fuji have such a great reputation for their colour science.

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 😄

1 hour ago, kye said:

It depends on how they've gone about making the chroma channel look like that.  Maybe they blur the crap out of it and the compression algorithm just goes "ooh, no detail...  wheeeee!" and auto-allocates it stuff all bitrate.

You do have to look closely at the images to notice (although once you see it you can't un-see it).

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.

55 minutes ago, kye said:

@Attila Bakos - great presentation!

It's nothing to do with resolution @tupp, otherwise the RAW files would be impacted too, it's processing.

I'm not convinced it's chroma NR either, as normally NR is just blurring.  Could it just be extreme compression?  If it gave the Y channel most of the bitrate maybe that's what happens to the colour channels?

Thanks! Double checked my files, it's hard to say. The EOS R has way more noise in the chroma channels, it looks like something that you'd expect from a log recording, whereas the Fuji is unnaturally noise free. Can extreme compression have this effect? I'm not sure about that. Also, why would they assign sooo low bitrate from the 400Mbps to the chroma channels? It doesn't make any sense as above 100 it's hard to notice the difference even in luma, and as I have shown in the video, you can have nice luma+chroma even with 100Mbps.

13 minutes ago, Django said:

Isn't this similar to what Fuji still users refer to as the "watercolor" or "worm" effect , especially present on foliage?

If so it basically has to do with the X-Trans sensor vs Bayer sensors.

I left Fuji system years ago (and partly because of such artifacts and color issues) but search for "fuji watercolor effect" and you'll find tons of talk about it.. 

 

This is not a demosaicing problem, it seems like some sort of temporal noise reduction applied to the chroma channels, as the first frame was always worse. I skipped the first few frames in each clip because of that.
H.264 and H.265 didn't make a difference. Long-GOP was marginally better in some situations, but generally it's just as bad as All-I.

47 minutes ago, tupp said:

However, it certainly appears that the Fuji chroma smoothing reduces the effective chroma resolution to significantly less than HD

 

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.

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.

5 minutes ago, gt3rs said:

here is powered over power bank 

 

Good to know, thanks.

3 minutes ago, herein2020 said:

I am also trying to figure out of the power port is USB-C or if it actually needs the full wall power supply which would be another major bummer since I already have a V-Mount USB-C setup for my other cameras.

From Newsshooter: "Canon has a new AC adapter for the R5 C as well as a compact power adapter and a DC coupler that features a dummy battery at one end. While Canon hasn’t stated that you will be able to shoot 8K 50/60p with a V-lock battery, etc. I think it is safe to assume that you could by attaching the DC coupler to another battery source."
So it won't be powered via USB-C, but you can probably find a solution to power it with an external battery.

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

13 hours ago, Sage said:

It must be pre-baked data sets of some sort ('assemble on site'). What Cpu are you rockin'?

It's an old i7-3770. One of the reasons I use Matlab is that many of it's commands are internally multi-threaded, it saves me a lot of time, especially with this old machine.

13 hours ago, Sage said:

I gave it a spin a few weeks ago; sometimes it works decently, and sometimes less so. Here's a comparison of GH5 and Arri, as well as their gradient charts:

 

Yeah, it's pretty far from being accurate. I wonder how they do their conversions on the fly, and what precision they use. When I build my camera matching LUTs it takes 1-2 minutes with all cores used to the maximum to build a size 65 LUT, they do it in a second or so.

1 hour ago, Simon Young said:

Would be interesting to know how Emotive Color stacks up against the new Cinematch plugin from the guys behind Filmconvert. From what I've seen it looks pretty promising...

I just tested it on some Sony A6300 S-Log2/S-Gamut3.cine and Fuji X-T3 F-Log/F-Gamut clips and if you're after a precise conversion, the results are far from great. It can still be a timesaver though.

Looks like they got inspired by 3D LUT Creator:

https://youtu.be/UxZxFWmTYg8

Just finished a new tool, it does what the title says. It's in beta, bugs are possible. [CLICK HERE]

Fuji just released the Bleach Bypass LUT, which has some weird transitions, so I'll use it as a demonstration.

This is the stress test image I'll use:

See what happens when you apply the Bleach Bypass LUT:

Now I use my tool in "box" mode with 1 iterations to create a new LUT:

This is "box" mode with 5 iterations:

More details on the site.

10 hours ago, androidlad said:

Well I guess it's called bleach for a reason... 😁

I'm sure you can fix it with your nice package of tools 😉

 

A simple LUT smoothing fixes it, it's easy to do in Matlab, but I couldn't create an online version yet. It's on the todo list