Nate… am I just on my own here?
EDIT: (a new development)
I THINK I HAVE FOUND THE ISSUE (or very near to it) !!
I just attempted the previous steps with a newly imported Minolta Autocord TMax400 roll and something interesting happened…
This is long, but please bear with me.
- As before, I added just basic scan info to just one of the .DNG files, e.g. camera make/model and film stock info.
- I then exported just that file to .JPG leaving default NLP metadata options but tick options to add to the same location, retain custom NLP metadata, add to stack. I also turned off any resizing or compression. The export went fine (as usual with non-sync-metadata files previously); the new .JPG appended the title, changed the camera information, etc. All looked well.
- I then used LR ‘sync metadata’ as before but to just two additional .DNG files in the folder. After sync I exported those, one at a time. They both worked without any problem just as the original did.
- I went back to the original .DNG from which the metadata had been synced and added all additional fields; e.g. shooting notes, digitization notes, lab details, etc.
- I then re-synced to the additional two .DNGs that I’d previously synced. I exported these one and a time once more and AGAIN both of them failed: camera info was still Pentax K-3, no title appending, no keywording etc etc.
- OK… I went to one of the synced DNGs and REMOVED the values in the NLP digitization fields (all of them). I re-exported and it WORKED!
- I went back to the original source .DNG and removed the same values from it and exported. IT WORKED.
- I again synced that source DNG back to the first DNG I’d modified (in step #6) - all values should be the same, the only difference now was that it had been synced, not manually adjusted. I re-exported the synced file (not the source) and IT ALSO WORKED.
- I then re-added the digitization fields info again to that synced file but OMITTED the camera equipement field (e.g. Pentax K-3 and FA50 2.8 Macro) and then exported it yet again. It did NOT work.
- I then once more removed all NLP digitization field values. And exported. IT WORKED.
- I did the same (step #10) on the original source DNG. IT also WORKED.
- I synced the source DNG back to the other two test DNGs (now with all NLP custom metadata that I desired EXCEPT for the digitization fields). I exported them again and BOTH WORKED.
- (lucky number 13) I then synced the source file to ALL DNGs in the folder (even those I’d previously not touched), picked one at random, checked the metadata and exported it to JPG. AND IT WORKED (as did 3 other spot checks including one of the previously sync’d files from the above steps.
So… there’s something going on, at least in my particular instance, with the NLP custom fields for digitization information. (shown in screenshot)
That was a long road, but sure hope it’s helpful.