XMP & RAW Files

[ajz]

I thought I understood the relationship between RAW and XMP sidecar files, but I am seeing XMP files being created even when I DO NOT check that box in the Catalog. I shoot primarily RAW. When I need vary large prints that go to an outside source I include the metadata using Cmd-S for the selected shots. No matter if the box is checked or not XMP files are being created for all RAW images. Upon download of any files "Copy" I do include my IPTC info for all of the files - maybe this is why I am getting those sidecar files. I am running LR ver 9.2, but the situation was there under 9.1. I am missing something obvious for sure. i have been using LR since ver 4, and do not recall this previously happening. Running on an iMac, the LR Catalog is on the main computer, all photos on external HD's.

I need clarity or more coffee. Any thoughts would be appreciated.
thank you,
aj

[digitaldog]

You are sending raws and XMP's for large prints?

You can turn it off, but it sounds like you want it on and it is....

Q. How do I turn off Lightroom’s Automatic writing of .xmp sidecar files again?
A. You turn it off by going to the Lightroom menu (PC: Edit), go Catalog Settings; click the Metadata tab, and turn off the checkbox beside “Automatically write changes into XMP”

[ajz]

I think I was not clear about my issue. XMP's  are always created, even when the checkbox in the Catalog window is unchecked. It is my understanding that the metadata and any alterations to the RAW file have to be kept in a sidecar file since these edits cannot be kept in the RAW file. But then why is that checkbox their - or not working in my case. I cannot turn it off. And, it seems recently that there was a down arrow, upper right on the images indicating that the metadata was not up to date in the LR Catalog. I might be doing something on import that I have never done before, but not sure what. The Metadata Panel shows that a xmp was generated. The checkbox seems to have no effect.

[Denis de Gannes]

Just one point, with Lightroom using the  Cmd-S function does exactly the same function as “automatically write to xmp”.
Lightroom by default stores the metadata in the Catalog file only.

[FabienP]

When exactly are the XMP files created, at the time of the import in the catalogue or later? Are you using any other programme that might be placing its stuff into XMP files?

Cheers,

Fabien

[ajz]

Fabien, et al - thanks for the reply s.

I have no programs other than LR 9.1 running on my iMac. LR  always makes a xmp file right next to my RAW image. The RAW image plus the xmp file show up on my external 3TB Photo Drive. I do NOT have "write changes to xmp" in the Catalog box checked. I thought the xmp files were kept in LR Catalog which resides on my iMac HD, apparently not. So, then what is the purpose of checking the "write changes to xmp" check box? Any time I write metadata or make changes in the Develop module to a RAW image, LR creates an xmp file?
So - where should the xmp files reside - in the LR Catalog on my iMac - or with the RAW image on my external drive? And, then what is the purpose of that xmp checkbox in the Catalog? I realize that xmp's are not an issue with other than RAW files. PLus I know that I can, if I wish, generate an xmp file with Cmd-S on my Mac.

thanks again


thanks

[john beardsworth]

XMP files are generated by LR only if that automatic setting is enabled, or if you do a Cmd S. I wouldn't waste any more of your time figuring out how they got there. All your work is in the catalogue.

[MichaelC]

“what is the purpose of checking the "write changes to xmp" check box?”

My understanding is that when the box is checked every adjustment/ edit is written automatically to xmp.

If it is left unchecked, the edits are only written when the cmd + s is used, as mentioned by John. If cmd + s is not used after the edits and the program is closed then the edits won’t be saved to xmp so next time that file is opened, the edits won’t show on the image/ file.

The unchecked option is given to avoid having every adjustment, including the ones that are undone, being written to xmp.

The reason that an xmp is being created in the first case could be because something is being done to the original file on import? As you said, you are including IPTC info on import so that has to go somewhere = xmp?

[Denis de Gannes]

“what is the purpose of checking the "write changes to xmp" check box?”

My understanding is that when the box is checked every adjustment/ edit is written automatically to xmp.

If it is left unchecked, the edits are only written when the cmd + s is used, as mentioned by John. If cmd + s is not used after the edits and the program is closed then the edits won’t be saved to xmp so next time that file is opened, the edits won’t show on the image/ file.

The unchecked option is given to avoid having every adjustment, including the ones that are undone, being written to xmp.

The reason that an xmp is being created in the first case could be because something is being done to the original file on import? As you said, you are including IPTC info on import so that has to go somewhere = xmp?

Lightroom default procedure is to save all the work you Do including the edits you apply to the Catalog file. There is absolutely no necessity or requirement to write to xmp. The application will continue to write to the Catalog file evern if you also write to xmp.
I have used Lightroom since its release in 2007 and have only used the option to write to xmp if I need to share a RAW file with another party.
The Adobe applications that require xmp in their operation to work with RAW files are Photoshop, Bridge/Camera Raw, xmp data can also be very useful to share data with other applications but they will not Read your develop edits.

[john beardsworth]

If cmd + s is not used after the edits and the program is closed then the edits won’t be saved to xmp so next time that file is opened, the edits won’t show on the image/ file.

As written, this is misleading. If you are using LR, you never need to do a Cmd S or Ctrl S - next time you open LR, you always see the edits.

The bolded line should read something like "next time that photo file is opened in another program such as Bridge, the edits won't show"

In LR, xmp is designed mainly for communication with other applications, and LR doesn't create xmp sidecars unless you do something, one or more of :

• enabled the automatic save settings
• done a Cmd S
• exported and chosen Original as the format

It won't create them anything upon import, not unless you enabled the automatic setting. Alternatively you might have used another application such as Bridge / Adobe Camera Raw which saves metadata in xmp files.

But they're just little files cluttering up your folders. No big deal.