Hi, perhaps a topic raised earlier. I just recently installed darktable 4.2.1.
Got a number of ORF files added to a library and these are looking fine in the “lighttable” tab.
However when a select one and switch to the “darkroom” tab I get a fully black screen although I see the image details ( shutter, f-stop iso ) listed below the black rectangle.
Anyone have an idea about whats’causing this?
Thanks Peter
Avonds, Peter & welcome!
Operating system? From where did you obtain dt 4.2.1?
I had the same problem this morning — but I am not certain that
the culprit is the same 
Please make this swift test:
When you have the black image in the darkroom tab,
open history in the left column.
Presumably, you will have color calibration as item 9 or so.
Click on the line below that (i.e. number 8 in my case).
Does the image appear?
If not: upload one of your ORFs here, so we can investigate further.
Have fun!
Claes in Lund, Zweden
Hi Claes, I run windows 11 , not exactly sure where I got the distribution from.
I opened history but don’t seem to have a color calibration. what I have is
0 original
1 raw black/white point
2 demosaic
3 input color profile
4 output color profile
5 display encoding
6 white balance
7 highlight reconstruction
8 filmic rgb
9 exposure
10 orientation
11 white balance (which I think I generated myself)
Hope this helps
Peter
not exactly sure where I got the distribution from.
???
Perhaps would be wise to find an official distribution
Please upload one of your troublesome ORFs here.
If you do not want to make it “public”, click on my avatar
and send it to me as a personal message.
Hi Claes, I got it from the “offical” site I think ( install | darktable.
I will upload a orf file but take note that there is not something like troublesome ORF’s.
My whole collection behaves the same way (they all turn black) .
Thanks Peter
P1080013.ORF (17.2 MB)
Works just fine here on Win 11.
And, as you can see, there is a color calibration step as item 8.
No problem here with your file. Can you also upload the XMP of the “blackened” photo?
And, if you click through your history, beginning from 0 original, is there a specific step that turns black?
Have you tried turning on/off/whatever OpenCL in the Processing settings?
P1080013.ORF.xmp (5.0 KB)
This is the xmp file - which is somehow “corrupted” because switching back to lighttable or even
restarting keeps the image black all the time.
will try the opengl setting
Peter
Hi Claes,
it looks like the opengl is the problem , turned it off and it seems to help. I will reload the “corrupted” image to see what happens
Peter
Hi Claes,
yes that is indeed the problem. Reloaded the file and I can switch back and forth between the two tabs without the image getting black.
Please note that the history tab still displays the same 10 steps and so there is no “color calibration” still , but perhaps it is not needed in this case.
Thanks for everything.
I am trying DT for infrared processing and can now address the next challenges 
Kind Regards Peter
Your going to want Opencl if you can get it working…might be able to by changing the resource setting and or making sure you have the very latest driver possible for your GPU… Do you have a dedicated GPU or integrated one by any chance.??
That suggests that you have your workflow preferences set to legacy or none - which I do actually. Means that just the White Balance module is used for WB, instead of the newer reference wb + color calibrations.
what are the pros and cons for this setting and where can I find this setting?
Pros and cons is a bit harder… with this option set to “scene referred (sigmoid)” or “scene referred (filmic)” the relevant tone mapper will be applied when one opens the image in darkroom, while the white balance module will be set to “camera reference” and the color calibration module will be used for actually controlling the white balance.
This can be more accurate and also lets you use more than one instance masked to different parts of the image, but with some cameras some initial setup can be needed for it to work properly.
I’m sure others could explain better!
P.S. My terminology was a bit wrong in my first reply - I’d forgotten that things had changed more recently.
P.P.S And this isn’t really related to the black image in principle - I get the impression there could be a bug causing that… not sure
