XMP files and Adobe Lightroom Classic CC

[RIMP]

Hi,

My workflow is to ingest RAW files from my camera card with PM, caption/keyword in PM, then import into Lightroom.     The captioning/keyword creation in PM creates XMP files.

I have been making keyword changes to my archive in Lightroom, and figured I should save the metadata changes to the files which  I thought would write to the existing XMP file.   I tested this in on a small number of files and found that instead of writing it to the existing XMP file that was created by PM, LR instead creates a second XMP file which isn't read by PM and as a result when I view the image caption/keywords in PM it shows the original unchanged keywords.

From what I can see when I view the two XMP files in Finder, the only difference between the two is the info listed under the 'Kind' column in Finder - the original XMP says 'Adobe Extension Information' while the new XMP file says 'XMP Sidecar'.

Please see the attached screengrab.

I don't understand why a second XMP is being created instead of the original being written to instead.   

I am using:
Macbook Pro mid 2015 with Intel Core i& and Mojave
Photo Mechanic Version 5.0, build 19749 20d085a
Also I have recently moved my archive from a LaCie external firewire drive to a Synology NAS RAID.

[Hayo Baan]

Looks like you have a case sensitive file system here and you uncovered an issue with PM in this case. Hopefully this is an easy thing to fix for Camerabits.

[RIMP]

Thanks Ben. Yes I think I have worked out that Photo Mechanic creates the initial XML file with the extension in upper case .XML.    Then when I'm working with the archive, which is stored on my Synology NAS that has a case sensitive file system, in Lightroom, Lightroom works with .xml files with lower case extensions hence it creates a new xml file.

Hope Camerabits support can help on this!

[Kirk Baker]

Unless I'm completely mistaken, it looks to me that Lightroom is working incorrectly.  The source image has an uppercase extension (.NEF), so any files associated with it should also have an uppercase extension (.XMP).  Lightroom should be creating/updating a file with .XMP as its extension.

To illustrate how this is wrong, consider the following case:

_001.NEF
_001.XMP
_001.nef
_001.xmp

This is completely valid on a case-sensitive file system.  PM will correctly read and write the metadata associated with each Nikon RAW file.  It sounds like if you had both of those images in your Lightroom library and forced Lightroom to update the metadata that it would only write to the _001.xmp file and it would cause stale data/data loss.

There may be a setting in Lightroom that allows you to have it pay attention to the case of the image extension when creating/updating XMP.

-Kirk

[RIMP]

Thanks Kirk.

Yes I have looked back through my archive, and my raw files have been NEF and Lightroom has been saving as XMP files.

Its only in the last week that I have switched to Synology NAS Raid where Lightroom is now saving lower case xmp.

There is no settting in Lightroom that I can find to set the case of file extensions.  Looks like I'll have to go to Synology and Adobe support.

Thanks for your help!

Richard

[imagetic]

After some extensive testing, Lightroom is indeed writing .xmp files, and macOS is displaying duplicate .XMP files in finder, Photo mechanic is reading/writing to the .XMP and lightroom is reading / writing to the .xmp.

Adobe support just tells me that no network storage of any kind is supported, which sounds like some mumbo jumbo if you ask me.  In all my years of large scale professional media, most of it has been with media connected over network storage.

But, I did test against an older synology NAS vs my new one, and the old unit doesn't have the issue.  So I think it's a mix of Lightroom being insane and something new/different about the Synology NAS / filesystem.

I'm not really sure where to troubleshoot from here, but at least I know I'm not crazy and it's not a Photomechanic vs NAS bug of some kind.

[imagetic]

Okay, last post on this one for the night...I'd move this out of PM support to general nerd support if I could...cause we're clearly dealing with another animal now. It's also 3am and I should probably stop writing things in public.

It appears to be some bizarre permissions issue with the NAS and Adobe Lightroom.  None of the other software has the problem, but if I have global / group permissions on an administrator user on a btrfs filesystem, it shows no user on the access for the volume in the macOS, it just says that I have permission to read write since I am an admin user.

If I assign my computer a dedicated user, and give it explicit read/write access to the folder, and not global admin privileges, Adobe will write to the .XMP correctly. I'm not even going to question why that is.  But I can update the XMP sidecar and pass it to and from Photo Mechanic and Lightroom now.

...at least from the testing I've tried so far.