Catalog size

[Adriano Dani]

Hello! One of the files in my LRCC catalog on macOS ("lightroom catalog-v13 previews.lrdata") is very large, already over 25GB, and I don't have many photos, around 1,000 to 1,500 RAW files. In creativecloud I have about 5GB occupied. It seems that this file increases in size exponentially. Does anyone know if this really works?

[Moved to Lightroom Classic forum by moderator, according to forum rules. This is about Lightroom Classic after all]

[Adriano Dani]

Just to be clear, I'm referring to LR Creative Cloud (CC), not LR Classic.

[Rob_Cullen]

""lightroom catalog-v13 previews.lrdata"" would be part of a Lightroom-CLASSIC v13 catalog.

So some confusdion in your question. Have you used Lightroom-Classic (or standalone versions 1-6) in the past?

[Adriano Dani]

I have used Lightroom Classic in the past, but currently I use Lighthroom CreativeCloud.

[dj_paige]

Lightroom (not Classic) does not use a catalog.

If your old Preview file from when you used Lightroom Classic is too big, you can delete it. (But delete only the previews.lrdata)

Better yet, please describe why you are so concerned about 25GB of space. Are you running out if space? Best to move the photos to an external drive rather than keeping them on your internal hard drive.

[Adriano Dani]

My concern is regarding the size of the files, since I don't have many photos. I can only imagine how big they will be when I have several thousand photos. I already work with photos stored on an external disk. I believe that this situation may have been caused by having used Classic previously. I understand that LR does not use a catalog, it is as if it used a single catalog, since it saves files locally. I will follow your suggestion of deleting this file. I am at ease because I have a backup of all the files (raw+xmp) on an external disk. Thank you for the tip.

[Conrad_C]

In terms of how storage space is used, there is no overlap whatsoever between cloud Lightroom and Lightroom Classic:

Lightroom Classic uses the …previews.lrdata file, which grows over time, but is just a cache so there is no problem if you want to delete it; Lightroom Classic will start over and build a new one as you browse images. Nothing you do in cloud Lightroom should change this file.

Cloud-based Lightroom uses its own separate cache for images temporarily downloaded from the cloud for viewing/editing. Nothing you do in Lightroom Classic should change this file.

One way to look at this: Suppose you used to use Lightroom Classic, but you switched to cloud Lightroom 6 months ago, and in those 6 months you have not opened Lightroom Classic. If so, then the last modification date of the …previews.lrdata file should be 6 months ago. So, if you look at the modification date of your …previews.lrdata file, is it not the same as the last time you used cloud Lightroom? If that is true, then that proves the …previews.lrdata is not in any way being affected by your use of cloud Lightroom.

The size of …previews.lrdata depends not only on the number of photos in the catalog, but also on the image quality settings in Catalog Settings / File Handling. Higher resolution, higher quality settings will create a much larger …previews.lrdata file than lower resolution, lower quality settings.

[Adriano Dani]

Hi Conrad, I understand that the catalogs are not overlapping. I found it very strange because I stopped using Classic over a year ago, when I started using LR Cloud (and uninstalled Classic), and the modification date of the ...previews.lrdata file kept changing to the date when I made edits in LR Cloud, giving the impression that the file (which should be from Classic) kept being updated. Since I have now returned to using Classic (with a new catalog), I will delete the previous files and uninstall LR Cloud. I hope that, in this way, I can normalize this issue of the "unrealistic" space occupied by these files. Thank you for your clarification.