OK. Seems I need to refine what I am doing. Thank you
there’s nothing wrong using raw denoise if it gives proper results for you.
There’s no better or worse if the result is ok for you.
Using darktable it‘s worth to keep in mind: there’s no one size fits all.
So the headline news a little amendment: … for images from my camera the way I process them.
There are several ways to denoise because all of them have their strength and weaknesses. It’s the result that counts, not the modules used …
5 Likes
As Martin says they all have strengths and weaknesses . My point was that out of the gate I think raw denoise is pretty heavy handed. In away most of them can use some tweaking and dialling back…
The YT video made some time ago by rawfiner is a nice overview of how to do that tweaking using the various modules in DT. All his videos are worth watching. This one is really good. A couple of the modules now have new names but the approach does not change…Denoising with darktable 2.6 - YouTube
@n01r , maybe you could post a raw and a sidecar to show how you process it, and we could try to come up with alternatives?
When the image is noisy, I don’t try to remove all of the noise, just reduce it. Noise destroys data; smoothening the noise completely will create the watercolour look. I try to get rid of chroma noise, and rarely apply luma noise reduction, as I find it hard to keep the details. Some of this is a matter of taste.
1 Like
I am not doing anything fancy, just raw denoise and denoise (profile) wavelet. I try to remove noise until it is not visible in the final image at expected viewing size.
As you say it is to taste, as is sharpening, and in some areas of photography, people can get very picky. I am happy that I can reduce it enough for my needs. I was just observing that, if I do it with Denoise (profiled), I get more artifacts, than raw denoise, but as someone said, maybe I am losing more detail with raw denoise. Anyway, no matter the method, I take the advice not to go too hard.
As kofa says it would be good to see an example. Then we are all talking about the same thing when we make comments. With the xmp files we can all see what settings and other modules are being used so we understand the full picture. For example it would be good to see what you call artifacts.with profiled denoise also when I have played with raw denoise in the past it has been my experience that just turning it on obliterate the detail so I am sure you tweak it and it would interesting to see your process
I just use the “chroma only” preset in denoise profiled, and that’s it. The remaining monochromatic noise is a part of my photo and it doesn’t bother me. I love that preset and I no longer stress about noise.
@n01r : if the purpose of the topic is to teach, to explain a technique you find useful, examples really help a lot. If the purpose is to ask for advice, then again, examples can show what you are struggling with.
The reason I use the contrast equalizer module to tackle luma noise is that it has minimal loss of detail because you can control the size of the wavelets being tackled. The denoise profiled tends to handle chroma noise beautifully and reduces luma noise. With contrast equalizer I only worry about the luma noise.
The sample image attached is left panel no noise reduction, centre panel denoise profiled, and right panel denoise profile and Contrast Equalizer used as shown in separate image. All of these panels have demosiacing sharpening from the new diffuse or sharpen module. Considering the high ISO and small image sensor I am more than happy with this result. Only a small section of the whole image is shown here.
1 Like
Thanks everyone. My question has been answered. I really just wanted to know if using raw denoise had any major downsides, and it seems maybe loss of detail would be the main concern.
Thanks for the examples.
denoise (profiled) also supports controlling noise suppression by detail levels. Have you tried that? Any experience with diffuse or sharpen to filter noise (it has some denoising presets)?
1 Like
The truth is that I am so happy with the default settings on denoise profile with my camera images that I have not invested time yet into manually tweaking it. With really noisy images I increase the strength of the default values. When I have a suitable image that justifies the time I may explore what you are suggesting.
2 Likes
Understood. I hardly ever use anything but denoise (profiled). I was only asking because you mentioned using contrast equalizer.
But I accept your challenge and will try one day to invest time in working out how the module works and how to get even better results. I am just amazed that with my cameras the module works so much better in DT V4 than 3.8. In 3.8 I only ever did the chroma noise in that module. I am also impressed with how well DT handles noise in general. I shoot a lot of high ISO images with a compact camera because I like to wander at night down alleyways and through street markets when I travel overseas. That is how I got the sample image I have used here. I want a non-intrusive camera so I use a Canon G16. Also a 6mm lens gives great depth of field at f 1.8.
We also have similar cameras in the family (a Canon G15, (un)used by one of my daughters, and a Panasonic Lumix LX-7 that I use).
If the G15 is as good as the G16 you should hang your head in shame. 
How to Denoise effectively:
First instance should always be Denoise profile wavelets (chroma), and use the curves for a specific frequency range. Second instance should be denoise profile non local means, dial the strength of the module to your convenience, I almost dial it down to 0,5 strength. After denoise apply sharpen with the diffuse module or contrast equalizer for frequency sharpening.
I haven’t seen the need for chroma denoise - maybe it’s camera dependent. I use non-local means at half, or sometimes less, as low as a quarter. A tip I picked up somewhere, is to use contrast equalizer to remove the artifacts from the non-local means denoise. I sharpen with diffuse&sharpen only in most situations it is enough.
I do not understand why RAW denoise is not used more often - unless it’s just that people like to keep to the same setup when dealing with jpegs. I use RAW denoise at a half usually.
Can’t speak for others . But i find it hard to get good results with it. It overdoes it or leaves stuff in that makes it ugly.
If i find the noise a problem (not often ) , just enabling denoise profiled is often a single click .
1 Like
I do not understand why RAW denoise is not used more often
Perhaps it depends on what camera make you have?