4 Replies Latest reply on Jun 13, 2017 5:25 PM by WobertC

    Discarding Smart Previews - lrdata size not reduced

    TheAnji Level 1

      I couldn't find the solution in the forums. so creating new discussion.


      I have Smart Previews, 1:1 and catalog Previews "lrdata" file of size around 20GB. I want to delete or reduce the size of this file as I no longer need previews for my whole old photos (I will build the previews again for the new photos import). I have discarded all the Previews from Lightroom. But still the size of lrdata remains same.


      I read in the forums that I can't delete these lrdata files. Is there anyway to reduce the size?


      Thanks in advance for your help.


      - Bhanu

        • 1. Re: Discarding Smart Previews - lrdata size not reduced
          Ian Lyons MVP & Adobe Community Professional

          Smart Previews are stored in a package ending 'Smart Previews.lrdata'


          To reduce the size of the standard preview folder you'll need to discard 1:1 previews. Fortunately, this can be done on a folder by folder basis.

          1 person found this helpful
          • 2. Re: Discarding Smart Previews - lrdata size not reduced
            TheAnji Level 1

            Thanks for reply Ian.


            I have selected the main folder where I stored all the years of photos and discarded the previews. Didn't work.


            I will try selecting each sub folder and discard the previews again. will update if that works.



            • 3. Re: Discarding Smart Previews - lrdata size not reduced

              Sidenote, If there is an issue with deleting the .lrdata files, I have not found what it is. LR will create a new file for you, but it will not contain any previews. You can always rebuild them. Maybe someone can tell us if there is actually important information in the .lrdata file that should never be deleted. Otherwise, WITH LR CLOSED, delete the large .lrdata file. But, as stated above, the Smart Previews are in the "Smart Previews.lrdata" file. And maybe someone can tell us why we should not be deleting that file.

              • 4. Re: Discarding Smart Previews - lrdata size not reduced
                WobertC Adobe Community Professional

                As I understand the Lightroom system-


                1. The  Catalog.LRCAT  file is the catalog that contains all your data and development work. It must NOT EVER be deleted. It must be Backed up frequently- But NOT in the default folder {Backups} that sits beside the catalog file.  Choose another physical drive location!


                2. The  Catalog Previews.LRDATA   folder should be considered to be a working "Cache" controlled only by the Lightroom program. It automatically creates ( and maybe deletes) all the views of the photos we see in the program interface including the 'Minimal' , 'Standard' and '1:1' previews we ask Lr to make when we import.  And also all the other sizes needed when we 'Zoom' an image view.

                You can delete this folder entirely and Lr will automatically re-create it.

                It cannot be selectively edited by opening any of the sub-folders.

                The Lr Menu { Library > Previews} allows some control over Standard (Build) and 1:1 (Build or Delete) previews. And in the preferences dialog you can set to delete 1:1 previews after a set time.


                3. The  Catalog Smart Previews.LRDATA   folder is something entirely different to 'ordinary' previews. This folder needs only to be used for two reasons-  (otherwise it does not need to exit at all..!)

                a) if you want to edit photos when the original files are not connected to the computer (eg. an unplugged external drive), consider Smart Previews to be 'proxy' images.   or

                b) you may achieve an increase in processing speed by setting the preference for Lr to use Smart Previews for developing.

                *If you do not need either of these there is no reason to have Smart Previews at all. (Delete it and never see it again)


                So to summarize-

                Do not touch the Catalog Previews.LRDATA folder, except to delete entirely- only if there is corruption problems.

                Use the Menu and Preference choices to control the 1:1 previews.

                Set the Backup catalog dialog to Optimize and Test Integrity of the Catalog.

                Only use Smart Previews if you have a specific reason.

                ScreenShot024.jpg  ScreenShot025.jpg