Lightroom : Artifacts appear on export in denoised regions

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  • Updated 2 years ago
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t seems artefacts appear when I export images that have been denoised. The effect is very strong, and make my images totally unsellable.

I tried different export parameters : 
- 100% jpeg quality
- Tiff without compression 16 bits/channel
- no sharpening on export
- sRGB or prophoto color profile

But the problems remains the same.
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Jérémie Fays

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Posted 2 years ago

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Peter Vogel

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It would certainly help, if you stated some specs:

- camera, file format you shoot and import into LR, RAW oder JPG? NEF, CR2 or something else?

- LR version you use and operating system

I shoot CR2 Canon RAWs, use LR 6.7 on Mac OS El Capitan and have just worked on over 200 raw files that all needed some denoising (+25) and slight sharpening and they all look fine after exporting as JPG in sRGB color space.

So, it doesn't seem to be a global LR problem;-)
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Jérémie Fays

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Yes, I use raw files form my Canon 5DmkIII, with the last version of LR CC (v2015.7 - camera raw 9.7) on Mac OS El Capitan.


Here are my sharpening & denoise parameters


Here is my rendering in Develop module


And here is the resulting export in jpg (quality 100% - no export sharpening)


I can make screenshots of 1:1 scale details, but the difference is the same. (just to avoid the discussion about the rendedering in develop module at scales different of 1:1)

The Library module displays a result similar to the resulting jpg. I'm quite suprised, as jpg conversion cannot axplain such a loss in quality !!
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Peter Vogel

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The only artifacts I see are in the dark background, when I look closely. Everything else looks fine to me. I don't know the whole image, but I do wonder, why you use denoise and sharpening at all on this one? How high was the ASA setting on that shot? On my CR2 files, I usually have to be over 1000 ASA before I even think about using those sliders. 

Since you set the sharpening mask to 65, there should be no sharpening happening on the background.

I use denoise for luminance or color or both only when I shoot very high ASA settings on my D5 Mark 2. Usually luminance will be sufficient and I don't recall ever setting the silder higher than 30. Usually it will be between 20 and 25.

So, firsI think that your settings are way too high for the image! And second I think that your image probably doesn't need any denoising at all?

Can you make a virtual copy of the image, set all settings back to default and then post the same screenshot again? This way I could judge better if sharpening and denoising is needed and to what amount.

Denoising gets rid of artefacts and if there are none, it might just produce them for you, if you set it up that high? That is my closest guess to your problem.
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Jérémie Fays

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Waw... I juste noticed a very strange thing : when I disable the use of the graphics processor, my develop module shows just the same crappy artefacts !!

that is coherent, but as you can imagine, the result I want is that of the develop module using the graphics processor !
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Jérémie Fays

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Here is the picture with no sharpening nor denoise. It is a 200 iso, but noise is clearly visible in the blacks, as I the picture was underexposed.




Not sure it will be visible at that size, so here is a 1:1 crop
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Jérémie Fays

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with no denoise, the rendering is very similar in develop and library modules. As soon as I denoise, differences appears. I get no clue why.
Because, regardless of the denoise parameters probably being  pushed too much, why should it be ok in develop and crappy in library/export ?
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Peter Vogel

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Have you tried exporting without the graphics processor ticked? Even though my graphics card is supported, I don't have that ticked, since it made LR unstable for me, it would crash unexpectedly. I have not tested it with the latest version, but I just read too much about people having all sorts of problems, when that is set to on. So, I would check, if the export file is different, when that is set to off.

200 ASA is certainly a setting where I would not use any noise reduction and I wonder that there is noise in the blacks, must have been quite a bit underexposed. But then, honestly, you really have to look hard to see that at 1:1. The pic will not be printed at 1:1, so nobody will ever notice that anyway.

Luminance boise reduction should do the trick by itself. I don't see at all, why you would also use the color noise slider? Maybe that generates that sort of artifact stuff, since there is no color noise in the blacks, I do not see any.

I would leave the pic as is, no extra sharpening and no noise reduction, if it was my shot. If you have ever seen the grain of an 400 or 800 ASA color slide film, your problem is peanuts;-)
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Simon Chen, Principal Computer Scientist

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@Jérémie Fays Given your description and the experiments that you did, could you check if your monitor's color profile is ok? The engineers here believe it could be due to a defective monitor color profile. 

To further rule out possibilities, could you post your original raw plus the sidecar xmp settings to some online place (CC sync or Dropbox) for us to investigate?

Could you also make available the monitor color profile that you use. What software / software options that you used to build the profile.
(Edited)
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Jérémie Fays

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Is there a private way to share the file ? It is a family session, and the parents don't wan't the photos of their baby published...
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Simon Chen, Principal Computer Scientist

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Thanks. You can send a shared link privately to me at sichen at adobe dot com.
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Jérémie Fays

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The color profile is here : https://dl.dropboxusercontent.com/u/10086379/iMac-27-Spyder
it was generate using the Spyder 3.
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Simon Chen, Principal Computer Scientist

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You might consider upgrading to Mac OS X 10.12.1 that fixed some of these profile specific issues. See https://feedback.photoshop.com/photoshop_family/topics/lr-v6-1-1-2nd-monitor-image-dullness-after-mi...