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

@andrew_rodney Not at 1:1. In full mode. Cleaning the cache or rebuild the previews doesn't work. Other collegues here have the same problem. It's only a problem if noise is addes in develop before.

Viewing at 1:1? 

Further, the only accurate way to view images is in Develop, again at 1:1 or greater. All other modules use a differing preview architecture.

Did you try rebuilding the previews and if not a fix, try cleaning out the ACR cache in Preferences. 

Pictures in Library Module has horrible noise if the picture has a little bit added noise.

Rebuild all your previews...

So does it matter if you're created Smart Previews in the past and are using DNGs? 

I think that with the last update, might be worthwhile to do a rebuild under those conditions, can't hurt and it's been a very long time since I've done so. Again, I'd hate to waste a lot of processing time doing this on tens of thousands of DNGs. 

Also I've just tested this with 1:1 previews and the issue is exactly the same.

Thanks, Is this since the update? To be clear this is 100% something that never happened until today. 

Thanks, I'll look into this if need be. Just wanted to post this here as I'm a professional photographer, editing hundreds of thousands of photos a year and this is the first time I've ever seen this issue. 

Also I just imported some brand new images into Lightroom to do a test and it's the same issue so I don't think a rebuild would change anything.

Some have found love after resetting the ACR cache data in preferences. 

Hi Andrew, I get that but I've used Lightroom for years and years and this problem is brand new to the new update. It's not a slight difference, it's a massive level of variance that's new.

The reason that Andrew's suggestion works is because it is forcing Lightroom to rebuild the preview but one at a time. So the solution is to force rebuild them all. 

Depending on the size of your library, this suggestion could take some time. Rebuild all your previews. My 650GB library of 35,000 images took a couple hours (6-core xeon, 64GB ram). This is primarily a cpu bound process so if you're on an i3 laptop with 8GB of ram and 100,000 photos, it could take a day.

My personal experience is that rebuilding the previews with each new version (8, 9, 10...) results in a more pleasant editing experience. 

In Catalog Settings, my preferences are: 

• Standard Preview Size - Auto (3840px)
• Preview Quality - High 
• Automatically Discard 1:1 Previews - Never 

There's a very good "how to" at PetaPixel.com titled How To Rebuild Lightroom Previews....