I’m still a bit of a novice on Darktable (DT). I have NOT been able to figure out how to tell what the dimensions (i.e., width & height) of an image file are. Seems like different units might apply but just knowing the number pixels is good for now.
My reason for asking has to do with some strange results. Most of the time the image files I create are the same size as the raw file that I’m developing which is what I’d expect unless I did something to change that. However, I’ve now experienced a situation where the aspect ratio of the exported image is quite different from the raw file and I have no idea what I might of done to cause this. In this case it is the height of the resulting image that was reduced.
Hoping this might be an easy one for experienced DT users.
OK! Thanks to Mica I now know how to find it but I’m still perplexed about what I did to change it.
A screenshot of info from the image in question follows:
Then a view of the EXIF data from my raw file follows:
And finally a view of the completed history stack follows:
My problem now is that I want to undo whatever caused the change in dimensions but without revising any of the work I intended to do when developing the image.
I think I found the problem. Darktable is NOT the only software that has the problem. It looks like my goof-up had to do with the camera setting which allows setting an aspect ratio. In this case, it was set to 16:9 which, I think, explains what happened.
However, the reason for shooting raw is that this stuff can be controlled in post processing. I know how to fix it in other programs but NOT DT. This was a hard image to develop and I don’t want to loose any of the stuff that affects appearance.
Hope there is a module that lets me say what dimensions to use for the exported images.
Just got a photo of EOS R captured in 16:9 from the internet. No problems here with aspect ratio, it’s exported as captured without having to set anything at all.
Some people already asked about your export-module settings.
Would you mind to show them? And if nothing else helps, share a raw + xmp?
Oddly that I think darktable doesn’t offer non uniform resizing, neither as a module nor during export. Even if you enter a 4:3 res in export, the photo will be fit into this frame by keeping the aspect ratio.
Following is my export settings where I changed to the size of the raw file. However, the resulting file has a height of 3776.
I’ve been hunting in the User Manual but find no mention of how the change from actual size of raw data to camera set aspect ratio is done. It looks to me like it happens very early in pipeline. For example, the crop module has a setting called “Original Image” for aspect ratio but it uses the 16:9 as original when the raw data is actually 3:2.
and I think there’s no way to tell DT to ignore this. ART / RT do ignore it and open the photo in 3:2. I don’t know if there’s a way to modify the metadata.
I made a sample. The raw has the 16:9 aspect ratio (6720:3776) but raw data is 3:2 (6720:4480). I didn’t do anything to change the neutral settings but did create a jpg with the size set in the Export settings as shown above (6720:4480).
Choose Pass through in Black/White point module. Use crop module to cut off the optical black area.
If I were you I would fill an issue at Github about this and link this thread. Probably Libraw that darktable uses for CR3 files.
I was able to update the metadata but Darktable (DT) was unable to process the revised file. After getting fatal error I did try to completely remove the former references to this file from the DT library. However, that didn’t help and of course if I had to do that it would be NO help in solving my problem.
The revised raw file follows: EOSR0189.CR3 (34.4 MB)
