P: Redundant copy of DNG and Tiff files when export from LRC to LR6

@Jim Wilde  Do you have an opinion as to which desktop app is behaving wrongly? As I read through this it looks like Lightroom Desktop?

By @Rikk Flohr: Photography

Rikk, initially I was going to say that LrD was the (only) culprit, but I just repeated the tests using both LrD and LrW....and LrW was even more problematic than LrD:

Using LrC I identified 10 images (4 x CR3 and 6 x DNG) which had been synced to the cloud, thus smart previews only in the cloud. I exported all 10 to a desktop folder as "original".

Using LrD I added 2 of the CR3s and 2 of the DNGs. Prior to the import I had 160 images in the cloud of my test account, after the import the count increased to 162 (the expectation is that it wouldn't increase at all). On review, the two additional files were a second copy of the 2 x DNGs. Reviewing LrC after the sync back, the two additional DNGs are new images, not VCs (VCs are what I would normally expect, but on examination the exported copies are a slightly different file size compared to the LrC originals, so that small difference is enough to ensure that LrC's duplicates detection fails to identify them as the duplicates that they are).

Using LrW I then added the remaining 3 x CR3 and 3 x DNG files, and this time the photo count increased from 162 to 168, i.e. ALL the new imports, including the CR3s, were seen as new files, not linked to the SPs at all. When sync-back to LrC finished, the 3 x CR3s had appeared as VCs of the original, as expected as the file-sizes matched the originals in LrC. The 3 x DNGs were again new copies, not VCs.

As an aside, I was wondering why exporting DNGs as original resulted in a slightly different file-size. Without doing a forensic inspection, I would guess that some of the keywords that are attached to the originals in LrC would have the "Include on Export" option unchecked, thus are not written into the XMP section of the exported copy. thus causing a small size difference.

If you need any further info, or tests running, let me know.

If you had already synced the photo in a Collection from Lightroom Classic to the Cloud, then that would be a lower res Smart Preview.

To get the full res into the Cloud you can just drop or import the original into the (Cloud Based) Lightroom Desktop.

This will replace the Smart Preview in the Cloud whilst retaining any edits made.

Is this what you are trying to do?

LrC does not have the ability to send full-size photos to the Cloud.

TBMK- You would need to run Lightroom (v6 Cloud based) on the desktop and Import/Add selected photo files which would replace the Smart Previews in the Cloud.