Some styles from darktable chart to try Do you want a straight out of camera JPEG style in darktable? Here we help each other - #51 by Peter
Hello,
I have used darktable-chart successfully some time ago. I think it was version 3.8 or 4.0. Now I want to create a new style with darktable version 4.2. but if I load the new exported pfm file in darktable-chart it is black. The old pfm file works fine. Do you know, whereās the problem with the new exported pfm files (everything is set right including the export in lab). Is there a know bug?
There was a window of time when it wasnāt working but it is nowā¦ bump up to 4.4.2 and it should be fineā¦
ups, excuse typo, my version is 4.4.2 not 4.2.
I think it has to do with the processing and upscalingā¦ if you have them set to yes set them to no and retryā¦ or the reverseā¦ I think one of those settings results in the black file issueā¦
Edit : I will try at home on my PC and confirm but it seems not to be working again at least when I did a quick build and installā¦
Perfect! Thatās it. Now it works again.
It works only if āallow upscalingā and āhight quality resamplingā are set to ānoā.
If one parameter is set to āyesā it will be black.
Thanks a lot!
Nice I thought I tried all combos quickly on my work PC and I kept getting blackā¦ Iām glad Zi was wrong on that pointā¦happy profilingā¦
That setting in the camera pertains to the embedded JPEG. The profiling software should be working from the raw image.
I have no idea why the author would think that to be important to camera profiling. AdobeRGB and sRGB are output colorspaces, and the camera only uses them to make the embedded JPEG rendition. Oh, and to stick a tag in the metadata identifying the output profile used to make the JPEG. It doesnāt affect the raw data one whit.
Iāve done a lot of camera profiling with other software, I know what the input data should be.
But Glenn, the whole point of dt-chart is to produce a darktable style to match the jpeg. So isnāt the jpeg relevant? Itās not classic ICC profiling.
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Just read the docs, thatās not profiling a camera.
Sounds good until āetc.ā, then itās now all this thing about making a style. Not familiar with thatā¦
I just saw āProfiling a cameraā in the thread title, and I have a pretty good grasp of that. Style-making, not so much. Iāll be quiet nowā¦ 
darktable 4.6 user manual - using darktable-chart 
@TimCoffey Iām not very well up on the dt-chart process, but I would think that AdobeRGB is what the dt-chart program is designed to deal with - the only difference from using sRGB (if the software was designed to) is greater gamut range, i.e. more points of reference.
In fact, in any situation, assuming that both the producer (i.e. camera) and consumer (i.e. software) are both using the same profile, the only difference in appearance between sRGB and AdobeRGB will be a slightly wider range of colours.
The only reason camera jpgs might look different in AdobeRGB is if the software isnāt reading and applying the correct profile/gamut/whatsit to display the file.
(happens often, at least on Windows.)
This is just my understanding - stand to be corrected!
Umā¦ what article are you referring to? This thread is about using darktable-chart. See the link I posted for @ggbutcher above.
After reading more carefully through your last post, it seems youāre referring to the color calibration procedure to produce a preset for more accurate colours, using a 24 patch (usually) colorchecker This is not related in any way to darktable-chart.
No you can choose a jpg image if the style is to match the jpg or you can just choose the raw shot for strait color correctionā¦ just depends which you use as the referenceā¦
Are you talking about using darktable-chart or color calibration?
Its important that @TimCoffey makes it clear which one he is talking aboutā¦ In one case you are using a function in CC module to obtain a set of channel mixer settings to improve the match of the camera input profile and with DT chart you are making a tone curve and a lut into a style to either do roughly the same ie better match color to the colorchecker or to match color and tone to a matching jpg shotā¦ in the former case you use the raw and in the later one you make a pfm file from the raw and/or jpg image and you tweak that to use LABā¦
I do recall AP talking way back that if you were printing to use AdobeRGB for export as without calibration it would likely be closeā¦ I think that is what I recall but selecting that color space is not part of the calibration process used by these methods as far as I know
I think it is not darktable-chart that @TimCoffey is describing so this is the wrong topic for this ā¦
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Yes, I think I posted on the wrong topic! Sorry!
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Tim, Iām sorry about confusing things. Your questions are legitimate, and deserve attention somewhere. If youāre really after camera profiling, I do know a bit about that and am more than willing to shareā¦
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No worries, all good!