Lightroom Classic Denoise: chromatic aberrations seem to return after denoise.

[laduerksen]

If I remove chromatic aberrations under "Lens Corrections" they seem to return after denoise.

Is this a common problem?

[Per Berntsen]

Are you viewing the image at 100% ?

[laduerksen]

Not sure how to answer that because I don't know what you mean by 100%. I normally crop these at a 1:1 with only a small black boarder at the top and bottom.  Then I view it on a 43" monitor at 4k.  I have a 50-500mm Sigma lens on a D810.  Sometimes I use it with a teleconverter and sometime I do not.  It is not unusual to get some Chromatic Abborations when you shoot such a lens a 500mm or 1000mm with a bright object on a black background.  It does not seem to matter how I crop or view the image the problem remains.

[Per Berntsen]

Not sure how to answer that because I don't know what you mean by 100%.

By @laduerksen

I mean 100% view, where one image pixel is represented by one screen pixel.

This is the only view that gives you a true representation of the image. Any other view will be inaccurate and misleading because the image has been scaled. 

Viewing at 100% is especially important when examining sharpness, noise, chromatic aberration and moiré.

If  checking the Remove chromatic aberration doesn't do the job, try using the eyedropper in the Manual tab of the Lens corrections panel, or adjust the sliders manually. Be aware that removing chromatic aberration in one part of the image might introduce color bleeding along sharp edges elsewhere in the image.

You can also try using a Defringe brush locally.

[GoldingD]

I noticed a article on the web stating that some edits in LrC should not occur before AI Denoise. That odd things may occur, that some edits might get thown out. I do not have that link at hand. But the following community page discussion on this exists:

https://community.adobe.com/t5/lightroom-classic-discussions/guidelines-for-order-of-edits/m-p/14046...

and

https://www.youtube.com/watch?v=fkrggaxUzY0

[laduerksen]

Thanks for the reference.  I will review it more.  However, doing the denoise first and then the lens corrections does not seen to work any better.   Although "Remove Chromatic Abbrations" removes some of the green fringe I still need to go into the manual mode to remove it all.  It seems like Denoise increases the chromatic abbrations and the checkbox cannot remove what was added by denoise.  On the original photo I did not noice any purple hue but once I run denoise I then do see a slight purple fringe as well on the bottom of the moon.  The results seem to be the same whether I denoise first and then do lens corrections or vice versa.

[JohanElzenga]

Denoise is done on the unedited image, so what you have done on the original image is irrelevant. After denoise has been performed and is saved as a new DNG, most edits are copied over however. I would expect that 'Remove Chromatic Abberation' is also carried over, but if it isn't then you can simply enable it again.

[laduerksen]

Remove Chromatic Abberations remains enabled after denoise.  However the green edge on a moon image that was removed before denoise, returns after denoise.  In order to get rid of it after denoise I have to go to manual Lens Corrections and move the green slider to the max setting of 20. and increase the green hue range.  Checking or unchecking the "Remove Chromatic Abberations" check box seems to make no difference.

[laduerksen]

Update: it appears that Denoise enhances chromatic abberations and the automatic lens correction does not fix the enhanced abberations only the original abberations.  Manual adjustments are required to handle the Denoise enhance part of the abberations.

Has anyone else experience this or tried this?

[Jao vdL]

Never seen this and I am not sure how that would be possible with what we know about the denoise algorithm but we really don't know much about it though... Does it also occur when you only do "raw details" in the enhance dialog? Is t perhaps more visible because of the absence of noise? Can you show some screenshots.