Culling layout (dynamic mode) does not utilize available screen space

[Betaminos]

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

Hi there,

I have recently started using Darktable and have noticed that the culling mode (dynamic) uses a layout that seems less than ideal.
To be specific, one image is fine as it will fill the empty space when zooming in:

Two images make sense as well as all the space is used:

Three images is where the issue starts, as there is empty space and even zooming in will not cause the images to take up that space:

Four images (the maximum that still allows for zooming) is using even less space, and zooming keeps the initial sizing as well:

This is on a 21:9 screen and running the latest version from AUR 5.5.0+904

Thank you very much for your time.

Steps to reproduce

1. Go to lighttable
2. Enter culling mode (dynamic)
3. Select three or four images
4. Zoom in

Expected behavior

The images grow to make full use of the available space (like they do when viewing only one or two images)

Where did you obtain darktable from?

self compiled

darktable version

5.5.0+904~g8d95339436

What OS are you using?

Linux

What is the version of your OS?

CachyOS (up to date as of 2026-04-06) running KDE Plasma with Wayland

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

AMD 9070XT and mesa (version 26.0.4-2 from cachyos)

[MStraeten]

so you expect the image height as is for full image view, but use max hight when zoomed in?

[Betaminos]

so you expect the image height as is for full image view, but use max hight when zoomed in?

Yes, exactly.
When fully zoomed out (or fitting the image to size) it should keep the aspect ratio, leaving empty space, and when zooming in it should grow the image to cover the empty space (vertical in my case).

I guess that running the screen in portrait mode would cause similar issues, with the space then being to the sides instead of above/below - I can test this setup this evening and provide screenshots to know for sure.
It would be great if - regardless of screen orientation - zooming in would cause the image view to grow to make use of all available space.

Update: Yes, portrait mode will also not resize the image's view to make use of available space.
This screenshot is showing four images fully zoomed in, with empty space to the left and right: