White balance presets for Canon M50 not visible

[mmhh76]

Hello!

I saw in the source code that finally the Canon M50 gets some support. Like White balance presets. But the problem is that I can't see any of them in Darktable. But they are in the source code, in src/external/wb_presets.c.

But I made it to work by changing all the lines that starts with in wb_presets.c:
"Canon", "EOS M50"

to:
"Canon", "Canon EOS M50"

and then compile. So now the presets are visible in Darktable.

I don't know why, because all the other cameras like M5, M6, M10 and so on are like "Canon", "EOS M10", but not M50. I don't own any other Canon M camera so I don't know if it's the same issue on them.

[cytrinox]

How do you open M50 raws? Please share a CR3 file (or if you are using DNG then the DNG file).
Edit: And please tell us which darktable version you use and if you manually applied any patches.

[Nilvus]

If Canon M50 use CR3, it's probably related as CR3 support is not integrated in darktable. Maybe white presets had been integrated but they can't be use without CR3 support. This support is work in progress and should be integrated in following weeks. You could check progress here: darktable-org/rawspeed#271

If M50 use CR3 support, I suggest you to close this issue and wait to see when CR3 support will be merged in link above. Or test the PR in link above and check if this solve your issue. If needed, you could ask later, when CR3 support will be integrated, to reopen it if you reprodice this issue.

[cytrinox]

@Nilvus WB presets, noise profiles etc. should apply to DNGs as well as to the original raw (cr3 in this case). That's why they already included, even if no CR3 support has landed in 3.6. I assume there is some difference in metadata encoding for Make/Model in whatever DNG converter was used.

[Nilvus]

@Nilvus WB presets, noise profiles etc. should apply to DNGs as well as to the original raw (cr3 in this case). That's why they already included, even if no CR3 support has landed in 3.6. I assume there is some difference in metadata encoding for Make/Model in whatever DNG converter was used.

On dng yes but how could darktable understand raw, so apply white balance, noise, etc, without being able to know and read the raw?

Just as a reminder, first step is to decrypt Exif infos to know which model/lens, etc. For that,it's exiv2 library. And exiv2 library that support CR3 has been released 2 weeks ago, and probably not updated automatically in all system.

Of course, it's also remains possible that some text needs to be updated in source code. Anyway, opening CR3 raw without CR3 support is not useful without last exiv2 version and without rawspeed support too.

Of course, it's different if using dng. But we lacks some infos as you asked, on this issue.

@mmhh76: please precise infos asked by @cytrinox AND which OS and its version.

[MStraeten]

might be a windows build since msys/mingw already includes exiv2 0.27.4 with BMFF support enabled

[mmhh76]

So sorry I forgot to add more information. But I tried it on Windows 10 and Ubuntu 21.04. Same result, no white balance presets for pictures taken with Canon M50. It's on the same computer. I compiled it with my changes on Ubuntu 21.04. I think it's a lot easier to do that in Linux. With my changes the white balance presets are showing.

Like I said, I changed all lines that starts with "Canon", "EOS M50" to "Canon", "Canon EOS M50"

I can't open CR3-files in darktable, so it's converted to DNG. I am using latest stable version of Darktable which is version 3.6. And white ballance for Canon M50 wasn't there in older versions. I was really glad when I saw it was finally included, but it's not working.

I used Adobe DNG Converter to convert CF3 to DNG and didn't do any changes in the settings. Just choose folders and then press Convert.

No patches applied at all. The DNG file is in this zip-file. It doesn't matter what CR3 image I convert taken with Canon M50. It's the same result.
IMG_2985.zip

[cytrinox]

Well, I think I know what happend here. Adobe writes the DNG EXIF Model tag with value 'Canon EOS M50'. But within rawspeed, each camera gets a clean name assigned, like 'EOS M50'. So darktable should show in image information the model 'EOS M50'. This is the case for Darktable patched with my CR3 patch, because then rawspeed has a definition (and clean model name) for M50 defined. And most profiles are made by people using my CR3 patch, so they used the "correct" clean model name.

But the official 3.6 build (to be precise the included rawspeed version) has no support for CR3 and thus no definition for EOS M50. In such case, Darktable uses the unmodified model name directly from DNG as reported by exiv2. You can check this in your Darktable in module image information, see model tag. It should be 'Canon EOS M50' for you.

So I would say there is nothing to do about this. As soon as there is a Darktable release with rawspeed including the correct definitions for EOS M50, it automatically fixes the issue.

I would not recommend to alter the model names, because this breaks everything once CR3 support is stabilized and released.

Edit: Another option for you may the use of my dnglab tool https://github.com/dnglab/dnglab/releases It writes the correct clean model name into DNG so everything included in 3.6 for EOS M50 should work for you.

[mmhh76]

@cytrinox Thank you, now I understand it. Until it get's fixed in rawspeed, I will continue to replace the names manually before I compile. It's nothing you do everyday anyway so it's not a big issue.

Thank you for telling me about dnglab, I will give it a try :).

[johnny-bit]

Essentially duplicate of #2827

track #2827 instead please.