Darktable on WIndows error: "HDRImage Failed"

Software HDRMerge
1

Hi,
I am new here and new to Darktable so please excuse me if this is something basic.
I installed the windows binaries for HDRMerge then installed it via the LUA script option. I started it and pointed it to the HDRMerge executable as instructed. Then I chose 2 JPG hi-res files that are almost aligned with different exposures. I also tested on the two NEF files for these (I use a Nikon camera). However, in both sets, the HDRMerge failed.

I don’t know how to begin to debug this or why it is happening. Screenshot attached. I am on Windows 11. Thank you for any help.

Screenshot 2026-03-10 160143
Screenshot 2026-03-10 1601431908×954 166 KB

2

Hi and welcome to the forum!!

If you open HDR Merge itself and select the two jpeg files, does it work?

3

HDRMerge only works with raw files.
Newer camera types are not supported.
You can convert these raw files to dng format.

4

No, unfortunately I get a black screen only.

Screenshot 2026-03-10 181743
Screenshot 2026-03-10 181743794×555 88.5 KB

5

I use a Nikon D750, not really a new camera, but it does use it’s own version of digital negatives (NEF files). I will try converting and test again in DNG format. Thanks

6

HDR Merge should work with the D750 raw files. No need to go to jpeg.

7

I tried with JPG, NEF and converting to DNG using the Adobe DNG Converter tool. None worked. Maybe I configured something wrong? What should I check? I tried the NEF and DNG directly in the app as well as in Darktable. Same issue, black screen in HDRMerge and error in Darktable.

I can send the files to my cloud drive if that helps.

8

Yes that would be helpful.

9

Do the images have any kind of compression applied by the camera? I know darktable often doesn’t support compressed raws from manufacturers because the compression algorithm is a black box.

10

Here are the files I am trying to merge, both NEF and JPG versions.

HDRMerge.zip

11

I wouldn’t think so. I believe I turned off all compression to have full-size files on the camera and then I can edit them in post. I know the NEF files don’t have any compression. I also tried converting to DNG and no go.

12

I just included the converted DNG files as well in the zip file.

13

I can only confirm, that I have been able to merge both nef and dng files without problems, using a Windows version, called HDRMerge_master_gaanedv0.6_release_64.
(No darktable or lua scripts used.)

14

Maybe it is my setup that is wrong. Where do I download that version? Github? I will try to find it and install it and see. I have v0.5 here. I tried in the app itself with out Darktable, and same error.