Extreme light-dark differences - ART vs RawTherapee [solved]

I’ve started with exposure +0.95 and sigmoid in film simulation +1.45 because i think this is a good starting point most of the time

What do you mean by that?
I can’t find this setting in your .arp.

Sigmoid (introduced in 1.21) is here:


(memo: fix typo in german translation for next release :face_with_spiral_eyes:)

Hello @apostel338
Yes, I found the tool, but what does @age mean by
… simualtion +1.45? These are his settings:

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I can see that you can do an incredible amount with masks in ART.
But the question remains:
Can this result from RT, which I did completely without masks, also be achieved with ART without masks? RT creates an enormous contrast compensation and yet it is not dull outside in the light, nature has a pleasant (local) contrast. Can ART do the same?
Ks_RT.jpg.out.pp3 (12.6 KB)

I suspect what he uses for contrast…

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This is only a dehaze tweak and the tone eq…no curves or other You could tweak the interior shadows/lightness to the desired level … no masks needed really… I didn’t analyse the RT edit or try too had to “Match” it…



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It’s amazing how few resources you need to achieve such good results. I have never used haze removal before. I will study it immediately.
Thank you very much.

But beware, I just noticed: Haze Removal makes strange irregular dark contours on the window.

Yes sorry, that is the module, I start with contrast 1.45 and skew = 0 but for this image I’ve moved a little the sliders.

After exposure and sigmoid I’ve used the tone equalizer and the rgb curve at very last.

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Ya it might have enhanced some CA on the branches… I really didn’t pixel peep at all. I am sure you could apply defringe or other CA tools to dumb that down… also in DT you can do this with the details slider and a channel mixer gray setting on the blue channel with low opacity… this will fade the blue out to grey…sort of desaturation effect masked to the details ie the branches…

There are many interesting approaches here, but so far none that surpasses RawTherapee.

Unless you use masks in ART, then the result is overwhelmingly good: Ks_ART-MK-2Masken.jpg.out.arp (13.8 KB)

Hence my big request to Alberto @ agriggio if you might be interested in developing the image with ART (without masks at first). (This photo itself is of course completely unimportant, but it is a good test file).
Can you please try if you can achieve the result of RT:
Ks.RW2.pp3 (15.3 KB)
Ks.RW2 (23.1 MB)

I am asking you because you know both ART and RT better than anyone else. I would be delighted.
And once you’ve done that, you can continue working with masks if you want.

Is there a reason why you don’t want to use masks? Local / masked edits are common to ART, RT, darktable, LR, etc. – virtually all image editors. They help solve otherwise-difficult problems that could be very challenging to deal with on a solely global basis.

Just curious.

Hello @lphilpot
I have nothing against masks, even though I had never used them in raw development until a week ago.
It’s about the following. I’ve been using RT for years, and after a lot of effort, I can do almost everything a photographer can only dream of with RT. I am actually very satisfied. I’ve been watching ART for a long time and now I find it so incredibly good, intuitive to use and somehow easier than all the others. Now I seriously want to switch, but with ART I should be able to get to the same level as with RT. And the comparison has to be honest: If I can get by without masks in RT, then that should also be the case with ART - for now. I’ve seen here in the thread what you can do with masks. I’m not ruling them out, not at all. Just not for this comparison. And if RT can do without masks what ART needs one for, that’s a big compliment to good old RawTherapee!
Your question is completely justified.

I think that’s flawed logic. :slight_smile: I’m not speaking for @agriggio but ART is (outwardly at least) a simplified RawTherapee. But it’s not RawTherapee and things are done differently in many respects. I’m not saying ART can’t go toe-to-toe with <whatever> since I’m no expert. But that’s not the point - It’s not a competition, either. You wouldn’t expect a monkey wrench and a pair of pliers to be used and function identically, even if they’re both designed to grip things. Maybe not the best analogy, but hopefully you see what I mean. I wouldn’t advise constraining ART to function just like RT, nor the reverse. Just use the tools available to their fullest extent and take advantage of unique (?) capabilities.

Hello @lphilpot
That’s an interesting approach on your part. Of course, I don’t want to declare a competition. I just find it difficult to do without the familiar quality of RT. I tried a lot in dt and got good results, but I never achieved RT. With ART I hope that I can achieve the quality, because ART is built on the basis of RT.
Maybe I want the good of ART without having to give up the good of RT.
My hope was and is that someone who knows ART very well can show me how to get the best out of ART before resorting to the masks.
But I very much hope that I don’t upset anyone with my wishes, that is not my intention at all.

this is not how I would normally develop the picture, but it’s the closest I could get to your RT version:

Ks.RW2.arp (11.3 KB)



Hello @agriggio
Yay, it works! Now I can see that you can get very close to RT without masks.
(RT has a little more contrast outside and therefore looks a little more unnatural. I can now see how extremely far you can go with contrast compensation).
With your .arp I now have a very good study object that I can learn from. It’s great to see how few tools you managed with.

Thank you very much.
Is there anything I can do for you or ART?

Just imagine how good your edits will be with masking :slight_smile:

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Hello priort,
yes, that is a great pleasure!
Now I see that ART is just as good as the great RT. That is very satisfying.

Alberto has done me a huge favor.

I’ve already got his settings down quite well, but I still have more to learn.
And then nothing will stand in the way of the masks.

You have all helped me a lot.
How nice that there is such good software in open source.

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I’m just a beginner… and I’ve done a decent research about which software I want to delve into - and found RT.
A bit later I also checked DT, and for some personal reasons - didn’t like it, then,
Here on Pixls - I found ART, and decided to check it as well, as I saw what people here do with ART, while I was finding myself working “extra” to get nice results with RT!
ART pictured as better suited “for the job”. Now - again - I’m only a beginner - “running around playing with sliders”, but still: The learning curve - for the very inexperienced (and still not really used to anything in particular) - is pretty much the same in my opinion.
I did get some very quick and nice results in RT, But I must say that ART is delivering me with the MORE satisfying results, especially on “harder” edits!

I can’t wait to learn more about masks and LUT’s!
ART is my new best friend! Thank you @agriggio :pray: