LR unexpectedly reset date/time of .dng...

Today I started LR, went to Preferences and under ''File Management'' checked ''Automatically write changes into XMP'', then closed the application. I found minutes later with Windows Explorer that the ''Date modified'' time stamp of all DNG files that are in my LR library is set to the date and time when I had LR running; however, I did not do anything to any DNG file, just checked that option in Preferences. I don't have an explanation for this. Any idea what could have happened?
LR unexpectedly reset date/time of .dng...
Yeah...you set it to automatically modify them with the xmp data, and it did.
LR unexpectedly reset date/time of .dng...
Mmmm.... I expected that ''Automatically write changes into XMP'' would make LR write any editing I make into the .XMP files instead of into LR database. I guess I was mistaken then. So what does that option do?

It exports the XMP to the DNG which changes the date on the DNG, but leaves alone the shoot date (listed as 'Date Time Original' in EXIF Metadata. That's the one that counts.



This data is Always written to the LR dB. It is only ever written to a file or sidecar 'at request of the user' including seting 'Auto export xmp'.



Don



Don Ricklin, MacBook 1.83Ghz Duo 2 Core running 10.4.9 %26amp; Win XP, Pentax *ist D

http://donricklin.blogspot.com/

Don is right, and to expand, only RAWs get side cars. JPEGs, DNGs and TIFFs get the xmp data embedded into the files themselves.

Don, Lee, sorry but I don't find the ''Auto export xmp'' option that Don mentions. Can you help me locate it?



On a side note, LR on-line help would be dead wrong because it states:



''Specify where to write metadata changes

Lightroom lets you specify where to write adjustments and settings metadata. The information can be written to XMP or to the library database. Keep in mind that changes made in Lightroom are not automatically recognized by other applications, when metadata is written to the library database.



In the File Management preferences, do any of the following:

To write adjustments and settings metadata to XMP, select Automatically Write Changes Into XMP.



To write adjustments and settings metadata to the library database, deselect Automatically Write Changes Into XMP.''

Auto write xmp data is in the main preferences screen.



The docs are correct, if a bit unclear. Changes are written to the library either way, but only written to the files if you tell it to, either manually or through the auto-write preference.

Lee Jay, the docs seem to be more than a bit unclear, they are out-and-out wrong on this issue.

Perhaps you are interpreting them differently from me. Why do you think they are just flat wrong?

The tech writer has a misconception, here. And QE did not catch it.



LR always writes to the dB.



Don



Don Ricklin, MacBook 1.83Ghz Duo 2 Core running 10.4.9 %26amp; Win XP, Pentax *ist D

http://donricklin.blogspot.com/

Lee Jay, I don't see where the writing is confused. It clearly says (my highlighting) ''The information can be written to XMP *OR* to the library database.'', which means it can be written to one or the other but not to both simultaneously.



This isn't confusing writing, it's just wrong.

Oh...I get it! Yes, now I see what you mean. The ''or'' is wrong since the writing always goes to the library either way.

And to be precise, Lightroom _IS_ writing XMP to the DNG file...it's not creating a separate .xmp file as it does with a proprietary raw file but it does write the XMP into the XMP headers of either DNG, TIFF, PSD or JPG files.



It's still XMP metadata, it's just being written to a file instead of an .xmp sidecar file.



And yes, it will ALWAYS write to the database...you can't turn that off. All you can turn off or on is the writting to xmp. Which I tend not to do for several issues. If I _DO_ need to get interchangable metadata (IPTC or CR settings) I will export the metadata on a folder by folder basis.

Jeff, thanks a bunch. You clarified the subject.



I wonder how that interacts with Camera RAW and PS File Browser (I still have PS CS).