P: Poor photo in the library and develop module - smart previews

I don't use DNG. I'm just only working with RAW Files from my Canon Bodys (EOS R & EOS 5DIII) and with tiff after editing with photoshop

Here's what he said......I don't see Mac listed.

He wrote this above:

Can you not comprehend this? Here is this the same on all PCs and MACs i have tested. 

Not that this has anything to do with preview interpolation algorithms. 

I suggest the OP export an image file with the issue to DNG file format and upload to Dropbox or other file sharing site. Then we can look at it on our systems for further troubleshooting.

The OP has tried BOTH Mac and Windows and sees the issue.

Here's what he said......I don't see Mac listed.

It's no matter if 'Use GPU for display' is activated or not. Both had the same result. And the problem occurs in 'filled' mode also.

OS: Windows 10 (latest)

GPU: NVidia Geforce GTX 1060

Andrew, I already stated Mac systems do not have the issue. You're using a Mac system correct? Give it a try on a Windows 10 system!

You are not making sense to me.

Yes I am on a Mac.

The OP has tried BOTH Mac and Windows and sees the issue.

The OP tried both with and without GPU.

Mac or Windows, what you reported about previews and interpolation algorithms is Unsubstantiated. 

So please explain to me what you are talking about.

Andrew, I already stated Mac systems do not have the issue. You're using a Mac system correct? Give it a try on a Windows 10 system!

Go for it and let us know what you find out.

I suppose since you never did, but made such reports of a code-base preview, algorithm change, I will do so. 

In the meantime, maybe you can explain what you see below, a preview in LR5 and a preview in LR10, both in Library, both from updated previews in each application using different preview/lrdata, that indicates why you believe, without any data from the team, that the interpolation algorithm changed. Both are zoomed to 33%. 

And if you would rather examine the higher resolution TIFF, it's here:

http://digitaldog.net/files/LR5vsLR10Lib.tif

This also sounds like speculation and it's easy for both of us to find out what's going on under the hood. I suggest one or both of us do so. 

Go for it and let us know what you find out. Whether it's an interpolation change that was implemented or a bug that was introduced LrC 8.4 does not exhibit the issue on the same Windows 10 platform using the same graphics driver. Either way it needs to be fixed. 

Whether the OP here is experiencing this issue or something else remains to be determined, but at least one other Windows 10 user at my report confirmed they can see the issue.

I have done this for the test

Then it is clearly not the GPU. 

Now can you tell us exactly what OSs (and versions of them) you've tested and better, can you upload a DNG with the edits baked in as well as the preview? Then others can load and test this under differing configurations and operating systems as well as versions of LR.

There's no need for anyone to speculate the cause, interpolation or otherwise but there is need to get to the bottom of the issue. What's quite clear is, it doesn't affect everyone. 

By intuitive reasoning after comparing images resized to 33% (i.e. 1:3) using nearest neighbor interpolation to the original raw file displayed at 1:3 Zoom. They exhibit identical artifacts.

That doesn't wash. Should we ask the Adobe engineers as you know we both can, so we both know the facts? 

Also as mentioned at the report, "I checked LR Classic 8.4 and Camera Raw 12.3 (most current) and they both appear to use bicubic or bilinear interpolation, which does not exhibit the artifacts seen with nearest neighbor interpolation.

This also sounds like speculation and it's easy for both of us to find out what's going on under the hood. I suggest one or both of us do so. 

And where did this change in interpolation algorithm you report come from?

By intuitive reasoning after comparing images resized to 33% (i.e. 1:3) using nearest neighbor interpolation to the original raw file displayed at 1:3 Zoom. They exhibit identical artifacts.

Also as mentioned at the report, "I checked LR Classic 8.4 and Camera Raw 12.3 (most current) and they both appear to use bicubic or bilinear interpolation, which does not exhibit the artifacts seen with nearest neighbor interpolation.