Noise reduction / sharpness help


I recently changed camera and started exploring the free alternatives for RAW development and after trying Darktable and Rawtherapee I settled for the last one since I like more the color rendition (I understand that I could get the same from Darktable but I lack the knowledge to use the color tools yet).

When I try to compare the final image I get from Rawtherapee and the software that come with the camera (Capture One Express Sony) I find that the result from Capture One is both more detailed and with less noise. I would like to use Rawtherapee since the Express version of Capture one is quite limited but I don’t manage to get the same results despite reading the tool description.

Is it because of some secret sauce algorithm or simply my lack of experience in RawTherapee ?

Full picture :

100% JPG crop from Capture One :

100% JPG crop from RawTherapee :

and for the fun 100% crop JPG SOOC :

The settings I used in RT :
DSC02852.ARW.pp3 (11.9 KB)


You can try increasing the luminance noise reduction slider and appling some sharpening (unsharp mask).

If you want you can share the raw file, so that people can play with it.
You should read here to explicity license your photo.


Hello Pietro (ciao?) & welcome!

I have a feeling that it is not noise reduction/sharpness
that is your problem… I fully agree with @sovereign
that if you share your raw file (i.e. not the jpg), the
forumers might come up with some nice suggestions!

You have a fine camera – but ISO 8000 have a tendency to be noisy :slight_smile:

Have fun!
Claes in Lund, Sweden

the “secret” is the recover details slider in the noise reduction module, and perhaps the gamma slider

I usually sharpen a little bit stronger, then I reduce noise heavily, and then I set recover details to perhaps 90, if there is more noise in dark areas I set gamma to maybe 1,15

It seems also that C1 output has a lot more local contrast.

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that too, yes

Thank you very much for the suggestions !

Here is a better attempt at the denoise, quite closer to C1 output.

and also the raw file if you want to play with it :

DSC02852.ARW (23.9 MB)

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

DSC02852.jpg.out.pp3 (11.1 KB)

this is RT 5.4 though

OK, thank you.

Please perform this swift test:

In tab 2 (Detail), turn Contrast by Detail Levels ON
(by clicking on the thing to the left of the title Contrast…
Click on Contrast + a few times and see what happens.

This is what I did (with the crop) in darktable. There is always a compromise between detail and noise.

DSC02852.ARW.xmp (4,1 KB)

I find that better than the C1.
Can you post the sidecar from this later attempt?

My version with Google Nik-collection Dfine2:


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As @gaaned92 said, it has to do with the local contrast. If you look at the original comparison, the shadow behind the sign is darker in the RT version than the C1, and yet the entrance roof tile has lighter greys. This means that contrast is higher globally but lower locally. This makes objects look sharper and more intense.

As for detail, the RT version has more detail and noise, except for the crushed black. This is evident in the wood grain (finer, more continuous) and on the tile surface (looks less like an illustration).

PS Dfine2 looks like a good compromise actually. I would go for something between that and the original RT version.

Here is another variation starting from the bundled High ISO Auto Matched Curve and then using Wavelet Edge Sharpening plus Haze removal and some more tweaking.
DSC02852.jpg.out.pp3 (11.7 KB)

The entire picture

Where do the blue patches all over the metal part come from? I do not see these in my version.


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I think it is the effect of the Haze removal module. Here is one without it (rest is same)


Just for information in real life it’s ceramic tiles, not metal and they do have a blue/gray shine in them.

It’s a small restaurant in the back alleys of Shibuya, Tokyo.
My original intention was a little more run down feeling for this picture, so I feel this version is a little too sharp but technically I bow to the result.

Clearly need to study more the tool !


Thanks everybody for the suggestions, I’ll download the pp3 files and have a look in detail.

Here it is my second attempt:
DSC02852.ARW.pp3 (12.0 KB)

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@sovereign quoted from RawPedia and @pittendrigh started a new thread on it. I think the language could be misinterpreted. Here is my explanation:

Denoising an image always reduces details, so I denoise only until a point where I start loosing too much details.
For me ISO 8000 is a ‘emergency’ setting when I do need short exposure in bad light conditions.

The picture was taken with an aperture of 7.1 and 1/80 sec. exposure. In my opinion this picture could have been taken with aperture 4-5 and an exposure time maybe at 1/40 or maybe longer dependent on your ability to hold the camera still and the shake reduction capabilities of the camera. In this case the picture could have been taken with a much lower ISO resulting in less noise.

With pictures at such high ISO values I did not find a way to completely get rid of noise and keep all the details that I want. So I only do whats possible without loosing too much details.

In Darktable I was able to get rid of chroma noise, all my attempts to decrease luma noise resulted in loss of detail. Finally I reduced noise using different methods with this result:

There is still much noise in the picture, but I did not want to loose detail especially in the wood contour lines.
Moreover, I did sharpen the image a bit.
DSC02852.ARW.xmp (8.2 KB)