I'm running Lr Classic on a iMac, with Big Sur. I have the setting to create xmp files ticked in preferences. If I edit a single image in LR, then an xmp file is created, but if I select file merge to hdr, and lr creates a merged dng file no xmp file is created.
It's only just started so I suspect a keyboard short cut / setting change, but can't find anything around this issue.
Any help grateful accepted.
XMP files are not created for DNG files.
The metadata is written to the header of the DNG file itself, so no XMP file is required.
That may well be true, but not the issue I'm facing.
On the 12th Dec, on the same machine, running the same software, the individual images that make up the HDR dng file have had individual xmp files created, even one for the actual dng file. Something must have happened between the 12th and now, has there been a software update?
Please remove the "Marked as correct Answer" .... I'm still having this issue
I also work with Automatically write changes into XMP checked in the catalog settings, and also routinely convert all my raw files to DNG, so I'm not getting any XMP files at all.
I checked some HDR files from 2015, and there were no XMP files.
Then I created a new HDR file with LrC 10.0, and still no XMP file.
When I open the file in Photoshop, and go to File > File Info > Raw data, the XMP data is there.
I am pretty certain that Lightroom has never created XMP sidecar files for DNG files.
For me, it's a big advantage not to have any XMP files, and that's one of the reasons for using DNG.
If you open an HDR file in Photoshop, can you see the XMP settings? If so, there is nothing to worry about.
Proprietary raw files are different, they will get XMP sidecar files when Automatically write changes into XMP is checked in the catalog settings.
RawDigger also displays the XMP settings.
Just a thought, what Per has advised is accurate with full info, the default when you are working in LrC the application is reading and writing to the Catalog File, the auto write to xmp is a secondary option however there is no option to automatically read from xmp.
As has been stated No XMP file is created for a DNG file because any and all info that Would Be written into the XMP sidecar fie on proprietary RAW files is written into, into a special area, the actual DNG file. The same is true for JPG, TIF, PSD and think PNG files edited in LrC.
Please show us a Screen Shot of your file manger program showing an XMP file that was created for a DNG file.
What I think you are seeing when you Merge several files is the old, Original, XMP file created for the original file that was included in the Merged HDR DNG image and that LrC Chose to name the HDR file as.
Nothiing happened on or just before 12th Dec. The XMP file you are seeing is not for the merged HDR DNG. Although it may have the same name as the HDR DNG it also has the same name as one of the files used to create that HDR DNG.
Move it out of the folder it is in with the HDR file and then do some edits to the HDR DNG. Is there a New XMP file created? I think you will se there isn't a new XMP created for that HDR file.
Here are a couple of screen shots, the 1st shows xmp files created for the individual image files used to create the HDR file. The time stamp on the dng is 18:58, where as the time stamp on the associated xmp is 19:05.
The 2nd shows dng files created as expected when creating HDR images, but no xmp.
I'm interested in understanding what has changed. I understand dng files have the history written to themselves, but that doesnt explain the difference between the two folders
And there are NO IMG_xxxx-HDR.XMP files in your screen shots.
There are IMG_xxxx.XMP files but None with the letters/Characters -HDR.XMP.
So your screen shots Prove you are mistaken and that Per Berntsen answer and mine are correct.
File time has no meaning. You do not have any XMP files for the Merged -HDR files.
So what you are saying is that the File named IMG_xxxx-HDR.DNG is Writing to the XMP file for the file named IMG_xxxx.XMP. That is NOT happening. All XMP files created by LrC have the same exact file name with the Extension different, CR2 and XMP respectively. As shown in your screen shots.
Sorry I misread your original post anmd the reply above.
LrC (and to my knowledge no other RAW/DNG Editor) has Never created a Sidecar XMP file for DNG files. Never Ever.
What would normally be written into the Sidecar XMP file is Written Directly into the DNG file in a Special place/section of the DNG file. That is also true for JPG, PSD, TIF and IIRC PNG files.
No Sidecar XMP was ever created for those file types listed above.
I know this because when I first stared using Lr (now called Lr Classic) back in 2006 or 2007 and did edits to Proprietary RAW files an XMP file was created next to those RAW file. Which bothered me. So I converted all my Nikon and Canon RAW files to DNG files so no XMP file would be created.
So from as far back as 2006/7 there has never been a XMP file creatred for DNG files.