clipping color channel, or what - how to solve this ?

Before I begin, I’d like to mention the images below are licensed Creative Commons, By-Attribution, Share-Alike1 (please help me correcting this expression if inadequately quoted)

I am a amateur/beginner using darktable 3.2.1 (under Windows) on Fujifilm X-trans files. I have 5 years of experience with raw file editing on LR 5.7. Sooner or later I’ll buy a new camera. So I will need a newer version of a raw editor, also sooner or later. Hence I decided to try darktable and hope to stay with it.

The picture and 2 sidecar files attached have been developed respectively using a scene-referred workflow and a display referred workflow in darktable. The result I have now is reasonably pleasing since I exercised drawn and parametric masks extensively. However I cannot get one detail solved. It is the line of red neon light at the left middle right below the long line of daylight fluorescent line. Changing the input profile into “linear prophoto rgb” improved it. The original raw file reveals the detail better. Also my (also attached) former creamy LR-developed jpg reveals it better. I guess the issue is clipping color channels, but I don’t know how to solved this.

MAC25640.RAF (32.2 MB) MAC25640.RAF.xmp (30.0 KB) MAC25640_03.RAF.xmp (30.2 KB)

I only see one attached jpeg, did you mean to attach more?

I can see my raf (Fuijifilm raw) and 2 xmp files included, and can download them. Not sure why you can’t see it.

The probem is that the highlights from the lamps are blown. Here an example using the tone equalizer one your second sidecar file.

MAC25640.RAF.xmp (29.3 KB)

My interpretation.

MAC25640.RAF.xmp (17.8 KB)

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Hey Thomas, THANK YOU.
While I have been using the tone equalizer before for shadow recovery and landscape lighting changes, I know appreciate its capabilities for highlight recovery.
Also thank you for sending your interpretation,hence some studywork for me ,like the intruiging 4 instances of the tone curve.
Again thanks.

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I’m messing with color handling right now, so your thread title caught my eye. I processed your raw with camera-provided parameters, except for whitebalance (I did a grayworld auto) and a fairly benign tone curve:

I don’t think the red neon is experiencing gamut clipping. The actual light right above it is well-blown, so I just let filmic desaturate it. Whether it’s the right tone is unknowable to me; you’d have to judge that on your recollection.

Extreme color problems will show up as “cartooning”, or posterization. I don’t see that here…


Thomas was right: it was clipping and I solved it with tone eqaulizer like this (attached). Thanks anyway.


I have been trying this for the first time in DT, and now I wonder: How do all the images you see on this page compare to what you saw with your own eyes? So, which one has colors and exposure that look like the real thing?

Hello Jack,
thank you for the interest in my picture. This photo was taken at nightfall. You can notice that the street lights are already on. So interpretations of this photo where the facade of this building is strongly lit do not correspond to reality. I must also admit that I only edit photos if they may fit into a project I’m working on (I am an amateur and photo art student). During that editing I try to emphasize certain aspects or make them stand out better. In this photo, it’s the group of people in the center left. The lady in red at the bottom and the man in the room above.
For the rest I use the jpegs from my camera of my other photos from travels or family events, without editing (or perhaps sometimes a bit of cropping or rotation in a simple tool).

Okay, so the first image on top of the page should be the one that looks most natural.
My aim (and what I’m looking for in a raw editor) is always to first try and find the best possible settings for a near to real look, like I have seen the situation with my own eyes. If I can accomplish that, I can always create different looks, dreamy, dramatic, whatever.

I know this is difficult, but should be less difficult with raw files than in the days of film when each film had its own unique color, grain and sharpness.