Improvement of blown highlights

I would like to present you a picture with overexposed clouds to see how the result can be improved. The building is the former Guild House of the cloth merchants in the city of Goslar.

The added jpeg is what I could do using Highlight Reconstruction mode “Blend” and Local Adjustments → Dehaze. What I don’t like here is the halo around the dark roof.

All in all, it is quite amazing what can be done here compared to the camera jpeg!

DSCF2837_RT-5.jpg.out.pp3 (16.9 KB)
DSCF2837.RAF (32.2 MB)

This file is licensed Creative Commons, By-Attribution, Share-Alike.


Nice photograph. My very quick play with this in GIMP.


I actually found the blown highlights the easiest part. The building angles were a problem I couldn’t tame.

improvement-of-blown-highlights-DSCF2837.RAF.pp3 (11.6 KB)
RT 5.8

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The building is not exactly rectangular :laughing:, it was built in 1484

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I also had a look at your sidecar and the problem is the combo of (very aggressive) dehazing via Local Adjustments and Local Contrast setting. I was not able to get rid of your halo with the tools you selected, although you can mitigate the effect by setting a better scope and shape detection.

You might want to have a look at combining the (less aggressive) dehaze tool with the Tone Mapping or Shadow/Highlight tool.

Although I did spend time on the sky I did not push it as hard as you seem to want to do: Bit to harsh for my taste, but to each his own, right :grin:

BTW: There’s some interesting fringing/CA going on if one isn’t careful. Especially the grey roof tiles.


Thanks for posting
darktable 3.6

DSCF2837_01.RAF.xmp (24.4 KB)


I will have to look at the pp3 files from @Soupy and @Jade_NL !

My dehaze setting is too aggressive, you are right!

Addition: both of you used CIE Colour Appearance Model 2002. I always avoided these atomic settings … but they have so much potential as you show me!

With Darktable from Git and using the new Diffusion module it is pretty straightforward to increase the contrast of the blown (is it really?) sky by masking it and then use the local contrast preset with around eight iterations. More is certainly possible but then we get into the same discussion as in the other thread.

DSCF2837.RAF.xmp (16.8 KB)


CIEcam is great, but…

You need to get used to it and you need to be careful when using it. It’s not all that hard to create artefacts and if this happens it is often in combination with a handful of possible other tools. Depending on the RawTherapee version you are using there are also some bugs that might still show up. Some of those issues have already been fixed in the very latest development version, though.

One other issue with CIEcam as currently implemented is that it isn’t ready for High(er) Dynamic Range images and/or wide gamut.

Jacques, one of the RT developers, is working on a Local Adjustments tool based on CIEcam16 and JzCzHz (=CIE L*a*b for wide gamut/HDR). If you build yourself you can merge the lagamcie branch if you are interested. This is still experimental, so no guarantees whatsoever! I have been playing with it and it is rather nice: The (fixed) power of CIEcam in combination with the flexibility of the Local Adjustments setup.

EDIT: Just remembered. If your French is good enough, there’s already some documentation about it: CIECAM02/fr - RawPedia

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Despite seven years of French at school and 45 years later several refresher courses, my French is unfortunately only mediocre. But I will try my best!
Thanks a lot for pointing me to this documentation

This looks great! No sign of overexposure and no peculiar transition from sky to slate tiles :+1:

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Tried to keep it sunny.

DSCF2837.RAF.xmp (18.2 KB)


Never considered using dehaze on the sky. Always learning some new happy little tricks. Thanks.

I kept it descreet, didn’t want to overdo it.

DT 3.7

DSCF2837.RAF.xmp (44.4 KB)

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Trying to enance sky and keep a natural look, DT 3.7

DSCF2837_02.RAF.xmp (16.6 KB)


Someone should try a perspective adjustment. :wink:

I tried a bit, along with the valuable suggestions from the pp3 files posted here. The results from DarkTable look great, I also like the outcome from GIMP!

DSCF2837_RT-8.jpg.out.pp3 (20.9 KB)

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Another try in GIMP. I attempted to bring out the colours in the paving and make the details a little clearer without the artifacts getting out of hand.

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Really nice how you make the three-coloured paving visible!

To which thread are you referring?

The filmic vs. color balance contrast thread starting around here.

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