Using 3DLut I get a message to use an invalid png, what do I have to do?

Using 3DLut I get a message to use an invalid png, what do I have to do?

I want to add that I work on Mac (Apple M2 Max) and that since today the sliders also do not work as expected since I try and use Darktable for now three weeks.
I also must admit not to even know, if I use the correct version of darktabkle.
(darktable-4.6.1-arm64) on OS Venture-13.6.5.

I really love darktable since I already used almost other like PS with LR, Capture One
with Affinity Photo and much earlier also ON1 and so on.

Thanks in advance and Kind regards,

I changed the category to Darktable to ensure the people knowledgeable in DT read your question. Welcome to the forum and I hope someone can answer your question.

Oh thanks for that. I was not aware of this. Where did I miss the category?

Kind Regards,

Could you share that png here? I would guess its dimensions are wrong or not supported.

Well, it’s just the png that came with darktable respectively taken from raw thereapee like it was mentioned in a youtube from Jörg Lang:
I was not aware to scale the pngs up?

Kind Regards,

Also, after scaling it up to 8500 by 8500 I get this message:

Bildschirmfoto 2024-03-20 um 22.59.10

Kind Regards,

P.S. and it looks different if not to say terrible.

the former message looked like this:

If that helps.

Also, got aware that I use a different LUT:

I tried to take the specific LUT Kodak Portra 800 2 out of the folder and move it to a different location on my HD, I still get the same message.

Scale? Where did you read about it? This will destroy the LUT encoded by such a png file. You must work with a pristine png file.

I just thought of it because of the answer from :
Bastian Bechtold


Could you share that png here? I would guess its dimensions are wrong or not supported.

For some reason this message does not appear anymore.

May I ask here as well, how the colours, being seen in Darktable do not appear the same way either in Capture One nor Affinity Photo?
The output, the export is done with Linear Prophoto - I also tried Adobe RGB which was not better. What do I have to use-which is best practise? I can easily fix it in both apps as it is just even more yellowish than it appears in Dark Table, though.

Thanks in advance and Kind regards,

P.S. If I want to donate to darktable, is this done here inside this forum? To PIXLS.US?
Because it is absolutly worth any donation. It’s a learning curve but results are way more controllable in my opinion.

Given the software reported I suspect you run Windows… So its a matter of making sure the color management is correctly set for all elements ie the OS and each software package…

DT has a display profile that will dictate how the image looks in DT and often its set to system so will use the OS settings which may not be what you want if the OS is not correctly setup…

To be sure I make sure I explicitly specify the icc file used when ever possible… For DT you would need to add that icc to the folder \color\out in your config directory. You might actually have to make this file if you are using only the internal files that come with DT it may not exist… Then specify the icc file for your monitor or if you have a calibrated one use the icc from the calibration there… I think you can specify the icc used in Affinity as well but I am not a C1 user so I can’t speak to the color management there…

I do have affinity photo as do several others so if you want to share a file we could compare in DT and Affinity and see if we notice any difference…

I am on Mac OS Ventura 13.6.5 but will have a look at my ICC profiles.
Thanks for that. Great.

Kindest Regards,

Nobody from the darktable project currently takes money/donations. pixls provides infrastructure and aid to photo projects, including darktable, and we do take donations. But donating to pixls is not donating to darktable, if that makes any sense.

Hi Todd Prior,

I have these ICC Profiles on my Mac:

How do I share a DT-File - it is simply a RAW file - how can I attach my settings?
Is it enough to have the XMP-with it?

These are two screenshots-named as where they come from:

Screenshot from C1 is the result from an export as tiff.

These are my corresponding ICC-Profiles in Affinity Photo:

Best or let’s say closest to DT it gets from AP with sRGB - unfortunately - the smallest
Colour-Space, as far as I know.

As of this reading best results are with linear ProPhoto RGB but still colours are too saturated.
With Adobe RGB it is completely off.

I attach the original file here together with the xmp in this wetransfer-link:

Thanks in advance and Kind Regards,

I’ll take a look…by default Affinity adds a tone curve to your raw… you will have some default processing in DT and C1 as well…Might be hard to get that to match from one to the other… Basically that studio icc should be the display profile in all of the programs and once you export a file from any of these as say srgb it should look basically the same ie the exported file in each of the 3. Now if the goal is to get the same output from 3 different raw editors on export that might be a bit more of an issue… I am on the run but I will re read your post again and I will fire up your file… I have ON1 and Affinity Photo and DT and RT and ART… so I can play a bit

I really can’t say about the color between editors. I don’t think you will ever get the same results but I might be missing the point…your xmp refers to a lut that I dont’ think I have or my location is different… In any case here are a couple exports from a quick edit… one done in relative intent and one in perceptual… I use an icc from for exporting… these are in srgb as I think still this is the closest gamut for most people…your mac is likely different…

SPK-Cafeteria-022_HDR_01.dng.xmp (11.9 KB)

Hi Todd Prior,
my issue is, that the exported-finally tiff file looks different to the settings in DT.
Either AP and C1 show a quite more saturated result, which then could of course be desaturated but I experienced that this leads not to the same result as it looked in DT.

So how do I tell all of them which colour profile to use? Colour profiles in DT seem to be totally different to C1 and AP.
C1 and AP seem to be quite the same in results.

Thanks for watching and Kind Regards,

Okay so an exported tiff looks the same as your edit if you pull it back in to DT?? But not when viewed in C1 or AP. and what profile are you using for export…you may have said but just to clarify…

So far I did not watch out on how an exported file from DT looks in DT. Because this makes no sense as none of my clients uses DT, of course.
My issue is that exported files from DT do not at all look in either C1 nor AP and so it would be with my clients of course.
My clients get handed over tiff files or maybe and only additional jpgs for easier handling purposes - and might use PS or Indesign or whatever.

As of this writing I tried the Profile: Display P3 which is the one, my mac display is using.
I must admit, that I never so far had any issues but also, I never used such a great tool as DT. I am simply not able to reproduce the reults from DT in C1, which is, especially with Fuji cameras, way better than LR in my experience.

I tried now P3 in all instances from: “Eingabeprofil” to “Ausgabeprofil” and Exportsettings as well - and it does not fit. Neither in AP from directly opening it without C1 and the same with C1.

Thanks for watching and Kind Regards,

So far I come closest to DT with all colour profile settings P3 and export settings sRGB.

Left hand side DT-right hand side C1.

Saturation is a little too much in skin tones and greens while it is less saturated in the red lights.

So by knowing some teeks, I can find a workaround - not completely satisfying but … .

I am interested on how to have these colour profiles work together in a better way though.

Anyway-Thanks and Thanks in advance and Kind Regards,

I would say if you use something like xnview and set the display profile to match what you are using in DT. Export your Tiff… Do they look the same…. If so your color management is working. Now if they look different in other Apps ie that exported Tiff then something is different about how they handle or the colormanagement settings used in those applications…

That’s all I can say… I will look to try with tiff to see if I can see what you see. The issue will be for you is that you have a Mac with it sounds like a better gamut than many other people might have on their monitors at least for now so you will need to nail down your color management ….

What are you exporting… 16 bit tiff files….

Well, xnview is for windows only, isn’t it?
Right now I am exporting 8Bit instead of 16 Bit. I was not able to see any difference but with my new settings I’ll give that a new chance.

What I had with some other images, same camera (gfx50r) the images looked totally different between Lighttable and Darkroom.

That was really strange.

Thanks and Kind Regards,