Yes I mean using RCM and am looking for Flog. The tool I meant was the one mentioned earlier by @tommyzenth “acesidtdctl”
I have also used some other Flog to aces transforms and they all have the same result. Is Fuji their own documentation wrong? Because they’re all using the specs as well specified by Fuji. Or are clipped highlights not supposed to be at the top of a waveform in ACEScct? I assume the transfers for Alexa do clip where I would expect them to clip.
I normally work with RCM and am trying out ACES because I wanted to learn a new thing. Not because I need to so it’s not a big problem.
Ah right. Did you compare within a manual setup with:
CST: Rec.2020/Flog → AP1/ACEScct / chromatic adaptation checked, no tone mapping, no forward or inverse OOTF
ACES Transform: ACEScct → Rec.709
And then the same clip with just an ACES Transform with the generated IDT → Rec.709?
Haven’t tested it myself but in my mind it should be the same. If you compared to using RCM you can expect different results because DaVinci DRT has different tone map than ACES, less contrast amongst things.
I did just now and your comment about tone mapping is what made it equal. Why does that happen? Clipped highlights on the Arri footage stay at 1023 on a waveform regardless of tonemapping. So why doesn’t that happen for the flog footage?
Can someone explain how to color grade X-H2S FLOG-2 footage in Davinci Resolve 18.6?
There is a lot going on with this conversation, which is great, except for the fact that I’m now confused.
You all rock, and I like to hang out with nerdy people who know what they’re doing and the tech behind this. I just need someone to explain to me like I’m 10 years old. I hope I don’t have to customize and do some C++ coding or HTML, CSS, etc…
I can’t seem to find a simple answer anywhere. Is it possible correct the colors with a few nodes?
Sure, where do you think you might be getting stuck? The general idea is to download and paste the DCTL code file into the right folder on your machine for DaVinci to use within it’s “ACES Transform” plugin (the DCTL makes an extra entry show up in the list of that plugin), and use it to transform the F-Log2 footage into a more common working space for grading (such as ACEScct or DaVinci Intermediate).
This post earlier in the thread from Shebbe summarized the process well, and they had a link to download their DCTL here.
Regarding your setup you have other inconsistencies as well.
If you decide to grade in an ACES pipeline I would recommend also grading in ACEScct. For manual colormanagement this means setting your timeline to ACEScct, not DWG/Intermediate.
ACES Transform: Fuji FLog2 to ACEScct
Grading
*** ACES Output Transform ACEScct to Rec.709.**
When I’m looking at the settings (on the color tab) for the ACES Transform node,
I have:
Is that right? I don’t see “ACES Output Transform ACEScct to Rec.709.” like above in my options. All I can see is EITHER one. I see ACEScct - CSC, or Rec 709. The instructions imply that there are two steps within that one drop down and I’m lost.
What I mean there is that you start with an ACES Transform node with the settings exactly as you show here. Optionally you can apply the Reference Gamut Compression if you have images with things like bright colored lights that are clipping.
Then on any subsequent nodes you place after, you are grading in ACEScct, the log working space for ACES. At the end of your node tree setup, wether that’s on the clip level or group or timeline level node tree, you apply another ACES Transform node with the input set to ACEScct and the output to Rec.709. That node will take you from the log working space you were grading in to the target display/deliverable.
The goal is to create what some folks call a “color management sandwich”. Input on one side, output on the other. In a large project you can take care of this at the group level, or make it into a preset (powergrade) so you can quickly apply this setup to all your Fuji shots going forward.
This screenshot is very helpful and looks great. I tried it out and I didn’t cringe at the visual result, which probably means its working
It was doing some weird stuff with the reds, but then again I added an additional serial node (in the sandwich) with only a LUT applied - the official FujiFilm FLOG2 LUT. To me it looks bad after I added it. however, I then went into the “Key” editor on the color tab, and brought the “key Output” gain to .5 and it looks decent to me now.
I have another question regarding this:
Since I went through all the steps to work in the ACES color space, does that then mean I DON’T NEED to use the FujiFilm provided LUT?
If someone knows how this works, my gears are turning…
Correct. The ACES pipeline is taking over handling of all that. The advantage of this is that other (non-fuji) cameras can also be mixed into this pipeline now, and they should all (theoretically) give a near identical look.
The Rec. 709 LUTs provided by manufacturers (or any output transform really) are their particular aesthetic choice on how to do output rendering, for better or for worse. There are a lot of opinions on
how it should be done. Same reason most “standard picture profile” modes on various cameras all look totally different. The goal of ACES is to standardize the output rendering, along with the rest of the pipeline for easier exchange. In theory any camera compatible with such system becomes effectively just a “fancy light meter” or perhaps a “photon collection device”.
You can of course swap the output with your own personal taste of color space transforms & LUTs, though at that point you are deviating from the ACES standard. That likely doesn’t matter if you’re working by yourself, but if you were producing a film with 20 VFX vendors involved and hundreds of people doing QC who all need to be seeing the same result, it might start to matter.
THANK you! This all makes sense now. I appreciate your patience with me as a N00B.
I tried researching on my own some of the terms, but it seemed to be circular definitions, and vocabulary out of my league. I ended up lost just trying to figure out which term was open in what tab of my browser and then decided to ask directly.
