Can't find denoised DNG file in Library module in Windows

 I had a huge folder - 32000 images.

This is a disadvantage when it is suggested to have just one catalogue. The catalogue can get huge, so when this issue occurs, it can cause a few headaches!

You will have to export your current catalogue, and you might have to divide it....

But then in the new catalogue, you can merge it.

This is from Copilot:

1. Open Lightroom Classic and go to the catalog you want to export.
2. Navigate to File > Export as Catalog…
3. Choose a location where you want to save the new catalog.
4. You can choose to include the original image files by selecting ‘Export negative files’.
5. Click Export, and Lightroom will create a new catalog in the chosen location.

If you’re encountering errors or issues during the export process, it could be due to missing images or other problems within Lightroom. In such cases, you can use the Library > Find All Missing Photos feature to locate any missing files before attempting to export again¹.

For renaming a catalog, you don’t need to export it. You can simply copy the catalog file (with a .lrcat extension) to a new location and then rename it as desired¹.

....

Creating a new Lightroom catalog and importing an old catalog into it is a straightforward process. Here’s a step-by-step guide to help you:

1. Create a New Catalog:

   • Open Lightroom Classic.
   • Go to the File menu and select New Catalog.
   • Specify the name and location for the new catalog folder, then click Save (Windows) or Create (Mac OS).
   • Lightroom Classic will reset and display an empty Library module, ready for you to import photos¹.

2. Import from an Old Catalog:

   • Still in Lightroom Classic, go to the File menu and choose Import from Another Catalog.
   • Navigate to the old catalog .lrcat file and click Open.
   • In the Import from Catalog dialog, set the following:
     • Check the All Folders checkbox in the Catalog Contents section.
     • In New Photos > File Handling, set the pop-up to Add new photos to catalog without moving (if available).
     • In the Changed Existing Photos section, set the Replace pop-up to Metadata and develop settings only (if available).
     • If some photos are duplicated in more than one catalog, and you want to keep both versions of the settings, check Preserve old settings as a virtual copy².

3. Backup Your New Master Catalog:

   • After importing, it’s a good practice to back up your new Master Catalog. This way, if you make a mistake or end up with an unexpected merge result, you don’t have to start back at the beginning again².

4. Clean Up:

   • Once all the photos are in a single catalog, you can finish cleaning up by removing duplicates, merging different versions of photos, tidying up your folder structure, and more².

Remember, when you upgrade a catalog, Lightroom Classic leaves the old catalog untouched, makes a copy of the old catalog, and renames its previews file. So, after the upgrade, you will end up with both the old and the new catalog files¹. If you need backward compatibility, keep the old files¹.

For more detailed instructions, you can refer to the official Adobe help page¹ or The Lightroom Queen’s guide on merging catalogs².