dallasinnewyork's profile

10 Messages

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174 Points

Wed, Feb 3, 2021 8:28 PM

Closed

Lightroom Classic: Noisy/Grainy previews in Library module

[See here for a precise recipe to reproduce the bug:

https://feedback.photoshop.com/conversations/lightroom-classic/lightroom-classic-noisygrainy-previews-in-library-module/601b076184b83c24bb8ece72?commentId=601d8be04b70bd4d8ebf27b4

-JRE]

Since updating to LR Classic 10, I'm experiencing a glitch in the Library module that makes some (most) previews render as noisy/grainy. 

When switching to Develop, the noise goes away once the image is loaded. But it returns when when switching back to Library. Only zooming into 100% or building 1:1 previews eliminates the problem. Anyone come across this or have a fix?

Screen recording of the issue.

I'm running LrC 10.1.1 on a 2019 15" MBP running 10.15.7 and working with Nikon Z7 NEF RAW files. 

2.3K Messages

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26.4K Points

10 m ago

First, try disabling GPU in the preferences (Preformance). Any better?

10 Messages

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174 Points

Thanks for the tip. Per your suggestion, I disabled the GPU & restarted LR. No dice. 

Incidentally, I did notice that just building standard size previews also solves the issue. Perhaps the existing previews are corrupt in some way?

2.3K Messages

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26.4K Points

Do try rebuilding them. Can't hurt. Also, keep in mind that the previews in any module expect Develop are using a differing preview architecture and are not expected to always match Develop at 1:1 or greater where you get the best preview accuracy. Images that are noisy when zoomed out, in either module will never show that noise correctly due to sub-sampling. 

My version shows 10.1.1, are you sure you've got the latest version? 

Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)

10 Messages

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174 Points

Totally understand that the previews will never be exactly the same. This specific phenomenon is new to v10, however.

My version shows 10.1.1, are you sure you've got the latest version? 

Yep, running the same.

10 Messages

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174 Points

I did notice that just building standard size previews also solves the issue. Perhaps the existing previews are corrupt in some way?

Hmmm, not sure if I was mistaken before or if for some unknown reason the behavior is now different, but today building standard size previews does NOT solve the issue. Only 1:1 preview or zooming to 100% does it.

1.2K Messages

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13.1K Points

10 m ago

I had a raft of minor problems that were cured by converting the whole library to 1:1 previews and setting the delete to never. Improved performance as well. 

 

10 Messages

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174 Points

Right, not a bad tip but I'd rather avoid the storage overhead that would require on my 100k+ image library 😬

(edited)

Champion

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6K Messages

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103.7K Points

10 m ago

Perhaps photos with noisy previews were imported with the option Build Previews: Minimal or Embedded & Sidecar?  What's the current setting of that option?

10 Messages

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174 Points

Good thought, but it's set to Standard. Furthermore, in the catalog settings, Standard Preview Size is set to Auto (2880), and Preview Quality is Medium.

Incidentally, all of these settings are unchanged from LrC v9.x

Champion

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6K Messages

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103.7K Points

10 m ago

You could try the sledgehammer approach, deleting the entire preview cache:

https://helpx.adobe.com/lightroom-classic/kb/lightroom-gives-error-preview-cache.html

Then right before going to bed, you could select all the photos in the catalog and do Library > Previews > Build Standard-Sized Previews, so you wouldn't have to endure mildly sluggish performance as you scroll through the library.

10 Messages

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174 Points

I guess I could try that, but given that newly imported images are also effected I'm not confident that rebuilding all existing previews would eliminate the issue moving forward.

Referencing my post below: I think what I'll do is to zero out the grain sliders for all newly imported images and only add the grain back in at the end of editing. Hopefully Adobe will address the issue soon in an update 🤞

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6K Messages

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103.7K Points

My bug recipe below shows that rebuilding existing previews gets rid of the noisy grain for existing photos but doesn't eliminate the problem for newly imported photos going forward.  

Also, adding the grain as the last editing step didn't get rid of the problem in my recipe.

10 Messages

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174 Points

Thanks for the bug recipe, you've nailed it. 

My suggestion to add grain at the end wasn't intended as a way of eliminating the issue but rather to mitigate it somewhat by making it the final step in the process, thereby avoiding the bug for as long as possible whilst editing.

10 Messages

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174 Points

10 m ago

New discovery. It appears that only images imported since upgrading to LrC v10.x exhibit the issue and only if the grain sliders are adjusted in the develop settings.

IOTW, same image + exact same develop settings with the grain effect turned off = no issue. In fact, with all settings zeroed out and only the grain sliders adjusted (even to a modest 25/50/50), the bug is replicated. 

This strongly suggests that the issue is LR v10.x is over-exaggerating the grain effect in the Library module. It's not just the loupe view, the effect can be seen in grid & survey views as well. Additionally, the effect is generally proportional to the amount of grain added.

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2.4K Messages

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39.2K Points

This sounds like the issue I discovered at the below report. LrC Applies the same Grain size to the lower resolution Smart Previews making it appear coarser. This can happen if you're using Smart Previews with the original files disconnected or when Edit> Preferences> Performance has 'Use Smart Previews instead of Original Files for image editing' checked.

https://feedback.photoshop.com/conversations/lightroom-classic/lightroom-classic-v10-poor-photo-in-the-library-and-develop-module-smart-previews/5f95f02a35f40c3a18c91af6?commentId=5fb3d3c4408c920f41a41a13&replyId=5fb3d3c8408c920f41a41a7c

Champion

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6K Messages

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103.7K Points

The bug here is unrelated to smart previews (see my recipe below).

10 Messages

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174 Points

it does sound similar but I can confirm that I am not using smart previews

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6K Messages

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103.7K Points

10 m ago

Here's a precise recipe for reproducing the bug. Note that the bug is *not* caused by the normal operation of the different preview algorithms used in Library and Develop, as demonstrated by steps 9-12 below:

 

1. Create a new catalog.

 

2. Set Catalog Settings > File Handling > Standard Preview Size: 1440, Preview Quality: Medium

 

3. Import a raw photo with a large, neutral area (e.g. overcast sky), setting Build Previews: Standard

 

4. Select the photo, go to Develop.

 

5. Set Basic > Treatment: Black & White

 

6. Set Effects > Grain > Amount: 50

 

7. Go to Library > Loupe ("e")

 

8. Observe the exaggerated grain compared to Develop ("d", "e", "d").

 

9. Exit LR.

 

10. Delete <catalog> Previews.lrdata

 

11. Restart LR

 

12. Observe that Library > Loupe grain is nearly identical to Develop grain ("d", "e", "d").

 

Tested on LR 10.1.1 / Mac OS 10.15.7.

(edited)

1.2K Messages

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13.1K Points

10 m ago

Many folks have been asking for enhancements to the grain slider, in particular, the ability to add more grain. Is it possible that Lightroom responded to that request? 

  

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6K Messages

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103.7K Points

The bug recipe shows that wouldn't be the cause of this behavior, since deleting the catalog's Previews.lrdata and restarting LR causes the Library and Develop previews to be very similar.

Champion

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2.4K Messages

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39.2K Points

I can confirm the issue is present when keeping the image in Color mode with both raw and JPEG files and simply setting Grain Amount to 50. It is also present with Standard Preview set to 'Auto,' which in my case is 2560.

No need to apply Treatment B&W or change your Standard Preview size to demonstrate the issue. It looks like the Grain setting is being applied AFTER the Standard Preview has been scaled. Since it is lower resolution the grain appears more pronounced. This is very similar to the Smart Preview rendering issue I mentioned, which appears more pronounced in both the Library and Develop modules because of the lack of properly scaling the Grain effect to the lower resolution of the Smart Preview.

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6K Messages

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103.7K Points

Note that simply rebuilding the standard preview causes the exaggerated grain in Library to go away.  So there must be two different code paths for building the preview -- one when coming from Develop and one when building it from scratch.