Deleting photos from Folders: When viewing photos in Grid view in the Library module (by selecting All Photos or Previous Import in the Catalog panel or by selecting a folder in the Folders panel), selecting a photo (or multiple photos) and tapping the Delete/Backspace key will display a dialog asking if you want to “Delete the selected master photo from disk, or just remove it from Lightroom (Classic)?”.
• Selecting “Delete from Disk” will remove the photo(s) from the catalog and move them to the Trash (Mac) | Recycle Bin (Win). Note: you can not use Edit > Undo to undo this action. If you accidentally removed a photo that you wanted, you will have to find the photo in the trash/recycle bin (through the operating system) and manually move it to where it belongs.
• Selecting “Remove” will remove the photo(s) from the catalog but leave them exactly where they were on disk.
When viewing photos in Loupe View or in the Develop Module, regardless of how many photos are selected, tapping the Delete/Backspace key, displays the same dialog as above, however only the “active” photo (the one that you are viewing) will be deleted (as opposed to all that are selected).
Or, you can use the following shortcuts to remove and/or delete photos while bypassing the dialog:
• Option + Delete (Mac) | Alt + Delete/Backspace (Win) will remove the photo(s) from the catalog but leave them) exactly where they were on disk.
• Command + Option + Shift + Delete (Mac) | Control + Alt + Shift + Delete/Backspace (Win) will remove the photo(s) from the catalog and move them to the Trash (Mac) | Recycle Bin (Win).
• Command + Delete (Mac) | Control + Delete (Win) will display the same dialog as above enabling the quick deletion or removal of photos that have the Reject flag applied to them.
Deleting photos from Collections: When viewing photos in Quick Collection (in the Catalog panel) or a Collection (in the Collections panel), selecting a photo (or multiple photos) and tapping the Delete/Backspace key will remove them from the Collection. To remove or delete a photo from the Lightroom catalog while in Quick Collection or a Collection, Control -click (Mac) | Right-click (Win) on the photo and choose “Go To Folder in Library”. Then, tap the Delete/Backspace key to delete/remove the photo from the Folder (or, use either of the first two shortcuts listed above).
When working in a Smart Collection (because the photos in a Smart Collection are based on search criteria), tapping the Delete/Backspace key will display a dialog with instructions to edit the photo’s metadata so that it no longer matches the smart collection criteria (or, delete the photo from the Lightroom Catalog).
Deleting photos from All Synced Photographs: When viewing photos in All Synced Photographs, (in the Catalog panel) selecting a photo (or multiple photos) and tapping the Delete/Backspace key will remove the photo from all synced collections (making the photo no longer accessible across multiple devices), but the photo will not be deleted from the Lightroom Classic desktop catalog.