kofa
(István Kovács)
August 14, 2023, 8:46am
28
Yes, you have made your point and your frustration is understandable. The trouble is, this is a user forum, not the darktable issue tracker (even though developers do hang out here).
To propose/request the change, please use the following link:
Better yet, comment on the already open issue mentioned above:
opened 07:11PM - 08 Sep 22 UTC
closed 12:34AM - 15 Jan 24 UTC
priority: high
feature: redesign
difficulty: hard
bug: pending
no-issue-activity
release notes: pending
**Describe the bug/issue**
If the highlights of the photo are close to the li… mit of dynamic range, the highlight slider of the perceptual briliance grading in the color balance rgb module produces artifacts when a certain threshold is exceeded.
This only happens in the default _darktable USC (2022)_ color space. In JzAzBz (2021) color space the slider behaves as expected.
**To Reproduce**
1. increase the exposure of the photo with exposure module until the highlights are at the limit of the dynamic range.
2. in the color balance rgb module, increase the value of perceptual brilliance in highlights using the highlights slider.
3. After a certain value, the artifacts - wide white spots - appear (see screenshot/video below).
**Screenshots**

**Screencast**
Short demo:
https://user-images.githubusercontent.com/38165484/189202459-4b598eb2-263c-421e-ba1c-e04402929b3e.mp4
**Platform**
_Please fill as much information as possible in the list given below. Please state "unknown" where you do not know the answer and remove any sections that are not applicable _
* darktable version : 4.1.0~git272.5a1a1845-1
* OS : Linux
* Linux - Distro : Ubuntu Studio 22.04
* Memory : 31,3 GiB
* Graphics card : NVIDIA GeForce GTX 1070/PCIe/SSE2
* Graphics driver : 470.141.03
* OpenCL installed : yes
* OpenCL activated : yes
* Desktop : KDE-Plasma-Version: 5.24.6
**Additional context**
I can't say for sure, but I suspect that this problem may be related to the
https://github.com/darktable-org/darktable/pull/12233
since this behavior appeared after that commit.
With enough info and convincing arguments, the developers may take it up(if you are not willing to take it up yourself). Please understand they may decide against it, or may have other properties.
Their solution/workaround was to disable filmic ’s highlight reconstruction by default.
You can see that some have picked up the discussion there, prompted by this very topic:
opened 07:11PM - 08 Sep 22 UTC
closed 12:34AM - 15 Jan 24 UTC
priority: high
feature: redesign
difficulty: hard
bug: pending
no-issue-activity
release notes: pending
**Describe the bug/issue**
If the highlights of the photo are close to the li… mit of dynamic range, the highlight slider of the perceptual briliance grading in the color balance rgb module produces artifacts when a certain threshold is exceeded.
This only happens in the default _darktable USC (2022)_ color space. In JzAzBz (2021) color space the slider behaves as expected.
**To Reproduce**
1. increase the exposure of the photo with exposure module until the highlights are at the limit of the dynamic range.
2. in the color balance rgb module, increase the value of perceptual brilliance in highlights using the highlights slider.
3. After a certain value, the artifacts - wide white spots - appear (see screenshot/video below).
**Screenshots**

**Screencast**
Short demo:
https://user-images.githubusercontent.com/38165484/189202459-4b598eb2-263c-421e-ba1c-e04402929b3e.mp4
**Platform**
_Please fill as much information as possible in the list given below. Please state "unknown" where you do not know the answer and remove any sections that are not applicable _
* darktable version : 4.1.0~git272.5a1a1845-1
* OS : Linux
* Linux - Distro : Ubuntu Studio 22.04
* Memory : 31,3 GiB
* Graphics card : NVIDIA GeForce GTX 1070/PCIe/SSE2
* Graphics driver : 470.141.03
* OpenCL installed : yes
* OpenCL activated : yes
* Desktop : KDE-Plasma-Version: 5.24.6
**Additional context**
I can't say for sure, but I suspect that this problem may be related to the
https://github.com/darktable-org/darktable/pull/12233
since this behavior appeared after that commit.