P: Denoise leads to odd checkerboard patterns in HDR images (dng)

Additionally, I am unable to download your files. Are permissions set correctly?

Note: This has been moved to the Camera Raw bugs section for accurate tracking. 

The failure is likely in the model code, not in the application, so we will track it in Camera Raw rather than the Lightroom Clients. 

If possible, ​@TUX24170726lkc9  please leave your files at the location until the team has a chance to review them. 

And how will Adobe evaluate this as a bug? They moved my post to “questions”.  The problem is that strong light-dark transitions are the very reason to use HDR — and the described behavior is reproducible in practically all interior shots, where such contrasts are unavoidable. 

Thanks for the originals and yes this is indeed a bug or a problem with the algorithm I think with the generation of the masks for shadows/highlights. It even does this if I denoise/raw detail the original files, export to tiff and then assemble the HDR from the tiffs and then hit denoise again. So it is about what happens when you denoise a HDR assembly with very sharp transitions that are slightly offset from 0 and 90 degrees and have shadows/highlights turned on.

That’s very odd. It appears to be a problem with the Shadows slider mask generation. The artifacts occur exactly where there are demosaicing artifacts in the image at the edges. 

AI denoise off and on below: You can see the artifacts happen exactly where there are demosaic artifacts. Does this also happen when you try the same thing with some of the individual images that went into the HDR? I am guessing this is caused by the interaction between the HDR merge and the demosaic and should not happen on individual images.