I've noticed that when I view my Lightroom DNG files via other software, it seems to be very hit and miss as to whether I see versions that includes the latest edits. I'm confident that the software (eg Plex or even just the Windows File Explorer thumbnail generator) is picking up the embedded JPG file, so I'm assuming that it is not being updated automatically every time.
The JPG is definitely updated if I explicitly select "Update DNG Preview and Metadata". I have seen some old threads that suggested that that is the only way to get the previews updated, but that is evidently not entirely true. I have done various test edits and I have seen many cases where the Windows Explorer thumbnail has updated. But there have been plenty of cases where it hasn't, and I can't work out why.
It does seem that edits done using "Quick Develop" in the library module don't cause an update, but more significant edits such as cropping in the Develop Module do tend to. But even that doesn't seem guaranteed. And I even saw one example where the preview got updated, but when I did a second update the preview reverted back to the original.
As I started out by saying, it all seems very hit and miss. Does anyone know for sure how it is *supposed* to work and/or how to get Lightroom to update the previews automatically EVERY time.
Yes, I do have the "automatically write changes into XMP" option set for the catalog.
Lightroom default procedure of operation is to read and write to the catalog. That said you can select "automatically write changes to xmp" however as far as I am aware this does not include writing the preview to dng files. That option is available from the Library menu bar, there is no suggestion that it happens automatically.
Thanks, and yeah, I understand what you are saying. But the reality is that is *does* update the DNG previews automatically. But only sometimes. That's what I am trying to understand.
or are you are saying that what I am seeing is a bug?
I see somewhat random behavior with this... sometimes the preview updates, other times it doesn't. Seemingly no rhyme or reason.