Exposure - Tone Curves profiles per brand (or camera)

Hello,

I am using a current nightly build RawTherapee_dev_5.8-2735-g8bb06c2_20210121.AppImage + stable 5.8 release, following issue is same in both …

I have new Fujifilm x100f (producing Fuji’s x-trans RAFs) camera and hit interesting issue with my beloved RawTherapee that I am using long time and that works greatly with Nikon RAW files.

If you open for editing the RAF files from Fuji, they have broken colours. After some test and trial, I’ve found, that Darktable works with them much better because Darktable contains a brand-like colour profile curves, see please here:

in picture above there are NO changes, just opened the RAF file with Dartable after deleting all previously created xmp and pp3.

Now if you open the same file in RT, you will get result like this

there’s just no other usable preset, loading colour profiles like this won’t help and so on …

So the only resolution was to create a Tone Curve profile for my Fuji (please don’t mind a Film-like flavour, I did it as for proof of concept) and suddenly the picture looks usable with this

my profile looks like this:

> cat ~/.config/RawTherapee/profiles/FUJI-x100f-C.rtc
CatmullRom
0 0
0.05 0.0344645
0.171948 0.17535
0.292675 0.402088
0.462864 0.68235
0.696062 0.936923
1 1

Summary:

Please consider adding a brand-like profiles whenever needed similarly like Dartable does. Default profiles are good with Nikon for example but obviously not working well with Fuji (at least) and it might drive away a less experienced users of RT because simply the out-of-box Tone Curve is meh while working with Fuji’s RAFs …

best regards, dan

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I’m sorry, but this forum is not the right location for feature requests. You’re welcome to use our GitHub page for that.

That being said, afaik RawTherapee has never been particularly inclined to include vendor-specific processing options. The philosophy is that you are the owner of your raw files.
The ‘Auto-Matched Tone Curve’ actually matches the tones of the image with the embedded JPEG. In most cases this works really well. So, if you set up your camera to an in-camera processing setting you like, RT should be able to replicate that pretty easily.

Edit:

Can you elaborate on what you mean?

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Please see screenshots … they are not

The ‘Auto-Matched Tone Curve’ actually matches the tones of the image with the embedded JPEG.

this obviously doesn’t work, check for yourself please

https://infophagia.com/ntz/paste/DSCF2735.tgz

embedded JPEG is something completely different that RT loads as with his Auto-Matched Tone Curve

Just for reference, this is the embedded JPEG:

This is the processed version in RawTherapee with only Auto Matched Tone Curve applied.

While the color in the sky is clearly different, I would say that overall the tonality of the images matches pretty well. There is room for improvement perhaps…

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Hello again,

There is room for improvement perhaps…

thanks for coming up to this conclusion … I still dare to say that it’s rather broken than anything else … let’s look on that like this:

if you open the file in competitors software (I’ve checked Darktable and Lightroom - I have these two installed), they look expectable and almost same whilst when you open these files with RT, the look is just broken (light in certain areas that the colours are washed out and too dark in other areas), look on this for example

https://infophagia.com/ntz/paste/DSCF2776.tgz

not best photo, it’s just randomly selected photo where are contrasts very obvious …

I don’t know how that Automatic Tone Curve is guessed from embedded JPEG but I dare to say with Fuji cameras it’s broken …

90% of people don’t think like that, they will only see colours that are washed out in RT and it will inevitably put the equal sign between RT = broken (+ 10% of them will hopefully add `with Fuji x-trans RAFs’)

regards, dan

If you haven’t done so already and have access to windows software, it might be worth using the dcp files from Adobe dng convertor. If you install this free program, you will find the dcp files for your camera under Progam Data / Adobe (in windows), which can be used in RawTherapee. In my experience this gives a closer match of the colours to the original OOC jpg.
Or just carry on using your own tone curve if that’s what you like the look of most…

While scraping non-free (as in speech) profiles from a free (as in beer) software may be a start for your complaining that RT = broken, it would be much more valuable to provide the required shots and help us create a free DCP for your camera and the sake of us all.

Hello guys,

I did, it’s what I am saying … I tried to extracting the dcp files from Adobe DNGConverter_12_2.exe but it doesn’t help … Those profiles has not much to do with Tone/Color Curve from embedded JPG in RAF …

I didn’t want to attach here those files because they are probably proprietary and everybody can download them for themselves … simply they don’t work … I’ve provided RAFs, you can test it for yourself with provided raws …

@floessie - please keep your tone civil … I am 20+ years linux guy who works in IT industry and who contributes his entire life to foss. I’ve created a bugreport here and provided all input as best I could do, I cannot contribute to this with code because I am photography user only … I’ve even provided the code for my Fujifilm curve that I’ve created based on Darktable Fuji-like profile … please see above …

regards, dan

Let’s avoid unnecessary generalization. You claim it is broken, others haven’t. We’re always interested in improving our software, but, for what it’s worth, we don’t care much about public opinion. It’s open source software, if they don’t like it, they can fork it and change it, or avoid it. It’s a free world :slight_smile:

As for the way RT works: the auto-matched tone curve option is enabled in the default processing profile, because in many cases it gives you a good starting point for further editing. But that’s precisely the point: it’s never meant as a one-stop tool, YMMV. You can choose an even more barebones starting point by starting with ‘Neutral’, which has all tools disabled. Or you can make your own processing profiles to accommodate your specific needs.

The point @Floessie made is that there are ways to improve the color rendition of RT when things are sub-optimal. Providing shots to create a DCP profile that we can ship with RT is a very good way to do that. Please see the provided link for details.

I assume you have found our GitHub and know that bugs and feature requests are tracked there? This forum is for discussion mostly.

3 Likes

I use a Micro 4/3 camera and I noticed that often the auto-matched tone curve yields a result that does not match the embedded jpeg.
I spent some time thinking about this problem, since I am confident that the auto-matched tone curve should work better, and that it works well for a lot of users.

Micro 4/3 wide angle lenses very often have a huge barrel distortion and I noticed that the embedded jpeg is a significant crop of the image that I see in Raw Therapee.

Is it possible that the distortion + crop combo creates a significant difference between the embedded jpeg and the RT image, so that the auto matching algorithm is fooled?

Maybe this also happens to Fuji lenses and this could explain the problem reported in this thread.

Does anybody know if auto-matching is performed before or after distortion correction? If it is performed before maybe performing it after could yield better results.

Hmm, interesting. The auto-matching algorithm is a cumulative distribution function based on the embedded image and neutral raw histograms, so yes, if the crop was significant it could affect the outcome. it will be image-dependent, as it will depend on how significant the contribution the cropped part of the image makes to the overall topology of the histogram.

Any camera that applies lens distortion correction in-camera will present this case. The Nikon Z lens system is apparently based on such correction.

2 Likes

Hello,

I dare to guess that this time there ain’t problem with distortion + crop … 35mm has very low distortion … Problem here is I believe with something else … attaching yet another RAF + JPG now with pp3 (unmodified, only opened file) + DT’s xmp

I can provide even more prominent example … see please the fancy shape of RT’s curve … RT really does something weird with reading profile from embedded JPG … I have no idea what more I can provide regarding this issue …

https://infophagia.com/ntz/paste/DSCF2782.tgz

regards, dan

Just a guess: Fuji internally underexposes the raw to preserve highlights and corrects this in the embedded jpeg.
Maybe auto-matched does not work well in this situation… @agriggio

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Hello,

underexposing `ist kain Problem’ but the shape of the Colour Tone curve is because the Auto-Matched Tone Curve seems really completely made up instead of derived from embedded JPEG …

this doesn’t seem an issue with other cameras - I can judge based on Nikon and Canon RAWs so far - I’ve never experienced that the Auto-Matched TC was so far by miles from JPG …

another think is the approach as whole - for example Darktable (correct me if I am wrong) rather apply a per brand/camera presets and at least in case of Fuji the results are much better than deriving that from embedded JPEG

You are right, there are no distortion nor cropping in your image.

I opened it in RawTherapee, selected the “Standard film curve - ISO Low” profile and the image was really underexposed.
Then I clicked the “Auto Levels” button and I instantly got a good starting point.

Can you try this and see if it’s any better?
https://bitbucket.org/agriggio/art/branch/fuji-histmatching

Hello Agriggio,

thanks for wonderfully quick attempt to fix it … may I please ask if you could be so kind and also continue on github issues page ?

thanks much, dan

This is a bit rich. You’re telling the person who built the algorithm in the first place and comes up with a potential solution that he’s not following procedure now?

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Don’t get me wrong, but that sounds a bit sniffy or arrogant…