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

[FeedbackCommunityMember]

I have a problem with version 10.0,
the photo is of poor quality in the library and in the develop module. I use smart previews (the disk with the original photos is disconnected).
smart previews in version 10.0 have poorer quality than in version 9.4
When I install the older version (9.4), the same photo with the same preset is of better quality (also smart previews).

It looks like there is a higher grain in the photo
Here are photos exported from smart previews.

Tested on: Mac pro 2013 (6core, 16gb ram, D500)

Macbook Pro 2014 2,7 ghz 4 core, 16gb ram

10.0:

Ver.10.0-b0348375-7ee4-43f6-bacf-3bf7316fa4d7-546901345.jpg

9.4:

Ver9.4-bc03ff63-1ef6-43e0-9ea4-dd2806a97943-358141873.jpg

Photo exported after attaching a disk with the original photo:

568_DSA7405-959a0e03-16c7-429b-8073-0ddca9b69679-298407583.jpg

[Melodic_wisdomB836]

 Hi all,

Problem is a little bit hard to explain so I've made a screen capture video to show what I'm talking about.

Basically since the new update images that have grain applied have VERY bad previews that make the photos look much more grainy than they actually are  until you zoom in and then zoom back which corrects the problem. If however you click away from that photo and go back to it the original awful preview comes back. Take a look at the video, I hope it makes sense.

This is ultra irritating for me as I often edit hundreds of photos at once and don't zoom in and out of each one as that causes Lightroom to generate a full size preview which takes a while. 

Thanks!

[TheDigitalDog]

The only accurate way to view your images is in Develop module and at 1:1 or greater. All other modules use a different and less accurate preview architecture. 

[COBill]

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....

[Melodic_wisdomB836]

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.

[TheDigitalDog]

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

[Melodic_wisdomB836]

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.

[Melodic_wisdomB836]

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

[Melodic_wisdomB836]

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

[TheDigitalDog]

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. 

[martinh25301180]

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

[TheDigitalDog]

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. 

[martinh25301180]

@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.

[TheDigitalDog]

So you don't see it at 1:1 right? 

When images are zoomed out, in LR or Photoshop (anywhere), all the pixels are subsampled down for the zooming out of the image. You can often see moiré and, in this case, the increase in grain. Which is why the only accurate way to view the image is at 1:1 (100%) which means one image pixel for one display pixel. Or greater. Depending on image content, in this case grain, or in other cases a pattern, a zoomed out appearance can look ugly but it isn't in your actual data. This is just an artifact of the preview process. 

[martinh25301180]

Sure. I know this. But normaly not so extrem. This is only since the last Version 10.0

[martinh25301180]

 The same picture in library mode in the old version

[TheDigitalDog]

What if you disable GPU in preferences?

[martinh25301180]

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

[martinh25301180]

The same. Can you not comprehend this? Here is always the same on all pc's an mac's i've tested

[TheDigitalDog]

Here is what I can comprehend: 

It's well know that Library and Develop previews don't always match and that the only accurate way to view your data is in Develop at 1:1. 

What I can comprehend and see is that in Library and Develop, at Fit and Fill, I do NOT see the same disconnect you show with images that have high ISO and thus grain. 

What I can comprehend is that perhaps, there is an issue on your end with previews (how they are built, your display etc). Because again, I comprehend by viewing the same images in the latest version of LR and earlier, they preview pretty much the same. 

Now you want to hunt down a fix for your issue or you're sure this issue affects everyone and thus, it's absolutely Adobe's fault? Maybe give us a better idea of your OS, version, display, video card etc, camera used, ISO, uploading a raw for others to examine etc. 

[martinh25301180]

Ok, you don't try it. This picture is no High Iso. It's taken by ISO 200. I only added a little bit of grain in develop  mode. Try it and you will see it.

[martinh25301180]

A lot of people in a german Facebook Group for Lightroom has the same problem. And this is the same also: https://feedback.photoshop.com/conversations/lightroom-classic/lightroom-classic-image-previews-with...

[TheDigitalDog]

I did try and NO I don't see it. 

You want help, find a fix or just complain? 

“My core belief is that if you're complaining about something for more than three minutes, two minutes ago you should have done something about it.“ -Caitlin Moran

Want to do something about it? 

[Todd Shaner]

I reported this at the below link and it was discussed at length. The Library module interpolation for 1:3 and smaller Zoom previews was changed from bicubic to nearest neighbor. This is the cause of the artifacts the OP is seeing in LrC 10.0, but not in older versions. The Develop module uses bilinear interpolation, which produces a more accurate preview. 

https://feedback.photoshop.com/conversations/lightroom-classic/library-preview-zoom-interpolation-ch...

[TheDigitalDog]

I reported this at the below link and it was discussed at length. The Library module interpolation for 1:3 and smaller Zoom previews was changed from bicubic to nearest neighbor. 

None the less, no, I can't produce this egregious difference in the two modules, after adding noise. I'm not alone. Yes, some are having issues. Is the goal here to rant or find what's going on and get it fixed IF it's solely an Adobe issue?

Here's Library vs. Develop on an image with grain; they are darn close and this is a 33% zoom:

This is the cause of the artifacts the OP is seeing in LrC 10.0

Then why isn't it seen above? 

IF the OP wants help, he now knows what kind of data to provide. If. 

[martinh25301180]

Ok, thanks. Had hoped this was a bug but if this was a new feature, then this ist horrible for me and my work.