Today’s Question: With a recent update Lightroom Classic said “What’s new December 2024”, which included “Discard Standard Previews – You can discard the standard previews to manage your disk space better by selecting Library > Previews > Discard Standard and 1:1 Previews.” I didn’t do this. Should I?
Tim’s Quick Answer: No, you shouldn’t discard standard previews in Lightroom Classic unless some of your previews are corrupted or you are in urgent need of free hard drive space.
More Detail: A recent update to Lightroom Classic includes a new feature enabling you to discard the standard-sized previews from within Lightroom Classic. This includes the ability to discard previews for selected photos, such as only the photos in a single folder. Before the addition of this feature, the only way to discard previews would be to discard the previews file associated with the catalog file, which would cause all previews to be lost. That, in turn, would require that Lightroom Classic build previews for your photos all over again as they are browsed, or in batch if you choose to do so.
If you are in urgent need of free hard drive space, you could discard the previews file to quickly recover some space. If you have built 1:1 previews you could also discard the previews file for that, which could potentially be even larger than the file for the standard previews.
However, you can also discard selected previews, such as if some of the previews aren’t updating properly. To do so, select the photos you want to discard previews for, such as by selecting all the photos in a given folder. Then from the menu while in the Library module choose Library > Previews > Discard Standard and 1:1 Previews. Note that there is not an option to discard the standard previews (approximately your display dimensions) without discarding the 1:1 previews (full-resolution previews).
Under normal circumstances you shouldn’t need to discard standard previews. In general, this should only be necessary if the previews are updated for some photos. If that should occur, you can use this new command to discard only the previews that are causing a problem, rather than having to rebuild previews for your entire catalog.
