Dan's profile

3 Messages

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126 Points

Thu, Sep 10, 2020 7:29 PM

Lightroom Classic: Camera Raw: Automatically write changes to XMP

1.) Lightroom’s option to “ Automatically write changes to XMP” is confusing.  Does this also write changes to DNG files?  This has always confused me as I use DNG files exclusively.  
2.) If LR catalog stores all changes to a RAW file, why does it always generate a sidecar file even when you have auto save to xmp is off?  

3.) My LR catalog recently went crazy and saved all Changes to 5k plus photos...it created sidecar files for CR2 files that were never edited (edits were in DNG only)?  I had been clicking save metadata option as I was working on just one file...it chose to do it for entire catalog.  Did I hit something in error?

Thanks in advance for your help.

Dan

2.3K Messages

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26.4K Points

1 y ago

Automatically write changes into XMP does just that, sidecars, inside TIFF/JPEG/DNG etc. Or DNG is updated via Command/Control S. And you can update metadata AND previews with another command there: Update DNG Preview & Metadata. 

I keep this setting on, but be aware it can affect your backup's such that an entire TIFF (or DNG) will be flagged to back up if any tiny change is made, even XMP. I don't care; this all takes place automatically for me at night. 

Yes, DNG isn't proprietary raw so no sidecar files necessary, XMP is inside that container. 

143 Messages

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2.6K Points

1 y ago

1) Automatically write changes to XMP creates sidecar XMPs for raw files but writes / updates that information to internal metadata fields in DNG and non-raw files (e.g., JPEG, TIFF, PSD).

3) Ctrl S (windows) or CMD S (mac) is the keyboard shortcut to Save Metadata to File. If you had lots of photos selected and tapped Ctrl S / CMD S, LR would have created XMPs for them all. Normally, LR will prompt with an "are you sure?" dialog when tapping Ctrl S / CMD S, but you may have elected to "Don't Show This Again" in which case LR will proceed to obediently write the XMPs.



1 Message

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80 Points

Infrastructure Engineer

 Infrastructure Engineer's roles include being responsible for designing, building, implementing and maintaining the IT infrastructure using the latest technology.

 https://www.fieldengineer.com/skills/what-is-an-infrastructure-engineer

1.2K Messages

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13.1K Points

1 y ago

Related: another advantage of this feature is that a Lightroom catalog can be recovered from the images. Back in the early days of Lightroom, a hard disk error corrupted the catalog in an unrecoverable manner. While I backup the catalog with every exit from Lightroom, I'd performed hundreds of edits and imports since starting Lightroom, all of which would have been lost if I'd used the backup. So I just deleted all the catalog files, created a new catalog and reimported. As all my images are in a single high level folder dedicated to this purpose, all it took was a couple clicks to get the process going. Took a couple hours but this was with a (compared to today) slow single core processor and EIDE hard drives.

Champion

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3.7K Messages

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61.6K Points

1 y ago

 2.) If LR catalog stores all changes to a RAW file, why does it always generate a sidecar file even when you have auto save to xmp is off? 
It doesn’t do that, unless you think that you need to save edits by hitting Ctrl-S (Cmd-S on the Mac). That saves metadata to xmp, but you don’t have to do that. Edits are automatically saved to the catalog.

1.2K Messages

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13.1K Points

1 y ago

Great solution until the catalog is lost in an unrecoverable manner. Then without the edits saved to XMP or the images, the only option is to go to the most recent backup catalog and recreate all your work since that backup. 
 
--------------------------------------- 
Rebuild Catalog from Photos 
--------------------------------------- 
 
If the catalog is corrupted in a way that it cannot be repaired by Lightroom itself, then it can be rebuilt from the photos AS LONG AS the setting to Save Metadata to file is set in the catalog. If this setting is used *1 then all the editing info is stored as separate XMP files for raw images or within the image for other formats such as DNG or JPG. 
 
To recover in this case:
 
1. delete all the catalog and cache files (or rename them temporarily) 
2. start Lightroom
3. create a new catalog when it tells you that the prior one is missing 
4. point to the highest level of the folder containing all your images 
   4.1 if you have your photos stored in multiple locations then do this 
       once for each location
5. import with the ADD option all your photos 
6. shut down Lightroom 
   6.1 choose optimize and backup catalog
 
*1 if the Save Metadata setting hasn't been used then: 
   a) turn it on
   b) in the Library module, select all your photos 
   c) use the following shortcut to have all the edit data stored 
      c.1) macOS: CMD S 
      c.2) Windows: Ctrl S 
      c.3) this will take awhile, depending on the size of your library and 
           the speed of your drive. The processor speed is immaterial. On a 
           12 thread processor, it used about 90% of one thread, 15% of a second 
           and occasionally a couple % of a couple other threads. 


120 Messages

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2.7K Points

1 y ago

Personally, keeping parametric/edit data separate from the base file has always seemed like a recipe for a future disaster to me - so I convert images to DNG as they're transferring from my CF Card - and everything is kept together in the one file (which is backed up).

That's my Bridge/ACR workflow - not a LR user, but I imagine that it can work the same way.

1.2K Messages

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13.1K Points

So protecting against a disaster is a future disaster? Using that logic, you should never take backups. 
 

120 Messages

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2.7K Points

Not sure how you made that leap. So just to clarify, it's your argument that "you need to keep parametric data separate from image data in order to protect it"?

I keep image and parametric data all in the same file. Simple. No potential for "sidecar files to get disassociated". No potential for "corrupted catalogs". No invalid logic that I can see there; nor any conclusion that I don't think backups are logical (I have about 150TB (not GB) of image data backed up).

1.2K Messages

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18.6K Points

I strongly prefer keeping RAW files in their original formats and having XMP sidecars. FWIW I'm a working pro and a longtime IT professional who understands the value and need for backups.

1.2K Messages

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18.6K Points

6 m ago

Lightroom has a database which stores edits to individual files as well as catalog information. Writing changes to XMP means that editing metadata is ALSO written to a sidecar file for RAW images, and into the file itself (for editable formats.)

Adobe used to use a Camera RAW database but eliminated that in a recent update so changes done in Bridge/Photoshop ACR must be written to XMP, there is no other storage location available.