Darktable 3.0.0 exports completely black images

Hey.
I installed Darktable 3.0.0 this morning and started editing some (newly imported and previously untouched) photos. When I exported them as JPEGs, some of them came out completely black. The Darkroom view also sometimes randomly went pitch black after using the exposure, denoise (profiled), raw denoise and crop and rotate modules (so far).
I had to adjust the crop to a certain resolution to get the darkroom view to show the image. But then if I disable the crop and rotate module, this happens:


EDIT: Using the black level correction in the exposure module also sometimes causes the Darkroom view to look like the screenshot.
Sometimes zooming in the Darkroom view also causes it or a part of it to go pitch black.
Unfortunately, I can’t share any of the raw photos but I’m sure there’s nothing wrong with them as they work fine in ACR.

¡Hola, @El_Artista !

Need more info.
Are you on some version of Windows?
Or on some sort of a Mac?
And from where did you fetch dt 3.0.0?

Have fun!
Claes in Lund, Sweden

Im on Windows 10 Pro 1909 64bit.
I got the official release of Dt 3.0.0 (darktable-3.0.0-win64.exe) from the website.

I have made a swift test on a Win X Pro 1909 machine, fetched dt 3.0.0 from the Web site & installed it. Imported an image and exported it into a .JPEG.

Sorry. I cannot repeat your problems. Everything went as intended here.

I wonder about your hardware, though.
Computer? CPU? RAM? GPU?
In dt’s settings, is openCL ticked?

Have fun (in spite of this)!
Claes in Lund, Sweden

I have an Intel i7 6700, 16GB of ram, and a GTX1080Ti.
Dt is using OpenCL.
I can try to check whether turning off OpenCL helps…

without providing the xmp ist hard to find what happened.
A guess: If you‘re using filmic rgb then you can switch preserve chrominance to luminance Y or max RGB since RGB power norm can be undefined for decent r g b values - this will be fixed in 3.0.1 (already done in current master)
It also is helpful to search for issues at Issues · darktable-org/darktable · GitHub first …

3 Likes

Turning OpenCL off in core settings seems to have fixed the issue. At least for now. JPEG exports are no longer empty (black) and the Darkroom view also doesn’t have any issues with any modules… I’ll see if reinstalling the graphics driver fixes the problem later.

1 Like

Same issue here, the lens correction module turns the image black, but when disabling it again, the export remains black …

Turning opencl off resolved the issue…

1 Like

Learning the new linear workflow, after watching Aurélien Pierres video’s and following different wonderful threads here, I encountered the same issues. The photo in darkroom turns black sometimes.
I disabled OpenCL, but the problem remains.
I’ve noticed the issue is happening using ‘local contract’, ‘shadows and highlights’ , when making use of Filmic RGB and/or Colorbalance. This isn’t always the case and I couldn’t narrow down the problem.
Anyway, I’ve read Aurélien Pierres latest article
https://darktable.fr/2020/01/darktable-3-rgb-ou-lab-quels-modules-au-secours/
and understood I’d better quit old habits : local contrast, shadows and highlights…
So the black screens will be lesser frequent and I presume a future update will solve it completely.

Practicing more and more will get me there.

I’m on MacOS Catalina.

1 Like

to understand the origin of the issue see #3865 (comment)
For very low values of r,g,b the denominator can be evaluated as 0 due to the used data types - this can differ when opencl is activated or not, but depends on the edit

1 Like

Is there a workaround?

Thanks. Preserve chrominance change to luminance Y did the trick.