OM-1 Support in Darktable

Thanks for the info.

I have no knowledge at all about programming etc., so maybe this is impossible or for some reasons not desirable, but would it not be a good idea to use Libraw instead of Rawspeed? As fas as I know Libraw is well maintained and it is used by ART, Affinity photo and probably more photography software and would not have to be maintained by the developers of DT.


Here is a branch in my darktable fork starting with 4.2 release tag. It should automatically pull rawspeed from the correct fork, supporting OM System and OM-1 camera. (WB presets and noise profiles for OM-1 are added to JSON files within the main darktable tree.)

To get the source code:

git clone
cd darktable
git checkout 4.2-om
git submodule init
git submodule update

To compile on Ubuntu I do:

mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=/opt/darktable/ ..
make -j
sudo make install

Running /opt/darktable/bin/darktable --version should give:

this is darktable 4.2.om1

In case your previous darktable version was earlier than 4.2, then running this will upgrade database and possibly config. One can run this newly compiled 4.2.om1 something like this to preserve the existing DB and config:

/opt/darktable/bin/darktable --configdir "~/.config/darktable-test"

Also added OM-5, cloning E-M5 III matrix data. rawspeed only, no WB presets or noise profiles yet.


Hi Jose,

I think I can compile Sarunas’ 4.2 version, I will try that in a couple days.

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hello Victor, thank you very much.
it is a fantastic present.
have a good day.

Hi, here you can download a Windows package for Sarunas’ 4.2 version with the OM1 (and OM5 if I understand correctly) support. Thanks Sarunas! Hopefully it will be merged soon to the main branch. Please let me know if there is any problem with the compilation.


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Thank you so much for providing this .exe ! I can confirm that the build installs and works on my Win10 installation.

I normally work in Linux, but have not been able to compile a version of dt that will recognize my OM1 on that system, so this really has saved the day for me.

Luckily, my computer is a dual boot, so I can at least get some processing done while I wait for a Linux version to become available.

Best wishes for a happy holiday and a healthy New Year.

Thank you!! It installed flawlessly and works well.

Thanks for posting this, but unfortunately, I cannot get it to “make”: many errors are thrown up.

I am in MX-Linux KDE 21.1 (based on Debian stable), so the instructions I need are likely somewhat different, and I lack the knowledge in Linux to find and apply them.

Initially, I tried editing the rawspeed file by adding the OM-1 camera info (a strategy that worked very well when I had a Fujifilm X-S10) but DT stubbornly refuses to recognize the .ORF files.

As a standby, I have the Windows version (kindly put up by Victor) but I’d rather work in Linux: it runs quicker, and draws less power allowing me longer between charges on my laptop.

I am not asking for assistance at this stage, just alerting you in case others complain the instructions don’t work. MX is based on Debian and Ubuntu is as well, but there must be some differences under the skin.


Michael P.

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all is ok.

thank’s again.


I forgot to mention yesterday that there is a workaround for not being able to open *.ORF files in DT with a standard install from the Linux repositories:

Digikam can open and edit OM-1 files without issues. Digikam also has a batch processing mode that will convert .ORF files to .DNG which DT can open and edit normally. I had some 200+ files from a recent photo excursion, and Digikam duplicated these as DNG in about 6 minutes on my machine - which is a fairly up-to-date i7 laptop. However, YMMV.


Michael P.


Great tip, thanks!

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@sugarbravo I’m not familiar with git. How do I add your branch to my current dt master so that I can use your rawspeed to build the latest version of darktable?

Thanks a lot!
I compiled with ./ --prefix /opt/darktable --build-type Release --install --sudo and everything went fine.
OM-1 files work without any issue with this fork.
Just out of curiosity: does it take a lot of work to adapt the master branch from the original DT repo to use the forked rawspeed? Is there more to it than adding the entries to noiseprofiles.json and wb_presets.json? It could be interesting to follow new DT developments even if the OM-1 is not added to the official repo.

I don’t think so, should all be contained in the rawspeed submodule (apart from those two json files).

Please note you’ll also need to build and replace your system Exiv2 with the one from the 0.27-maintenance branch to get full metadata support for OMDS cameras, for e.g. lens detection etc…


Did you install all dependencies for compiling darktable?
Here are some instructions for building DT: GitHub - darktable-org/darktable: darktable is an open source photography workflow application and raw developer
The exact names of the dependencies may differ from one distro to another.

OK, that is good to know.
Thanks for pointing out the exiv2 version issue. I noticed that I don’t get all metadata in darktable with exiv2 version 0.27.5. I get or just ‘-’ for several fields. I’ll need to try the maintenance branch.

just for information, by changing the extension of the ORF file to CR3, Darktable opens Libraw and decodes the files of OM-1, …
seen on the French forum: De la triche


I doubt I had all dependencies there - the error messages I got supports this.

Thank you for the link. It’s so very much appreciated. I’ll give it a try and if I’m successful, I’ll report back here.

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