Lightroom Classic: Date Time Digitized won't refresh from file

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  • Updated 3 weeks ago
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  • (Edited)
I'm using ExifTool to update the date EXIF tags in some photos that are already in my Lightroom library. After making the changes, I can use Metadata -> Read Metadata From File to read metadata changes into Lightroom. This will properly update the "Date Time Original" field of the EXIF metadata panel.

Unfortunately, reading the metadata does not update "Date Time Digitized" field. I continue to see the "Date Time Digitized" as it was set when the file was originally imported.

The same bug seems to apply to "Date Time"—again, changes to the file are not reflected in the metadata panel.

Step by step:

1) Import a file, D40 2007-08 9001.JPG

2) Observe "Date Time Original" and "Date Time Digitized" in the metadata panel: both are 8/17/07 3:16:51 AM

3) Run ExifTool, changing all dates to 2007:08:17 14:16:51

4) Confirm metadata settings with ExifTool:
-EXIF:ModifyDate=2007:08:17 14:16:51
-EXIF:DateTimeOriginal=2007:08:17 14:16:51
-EXIF:CreateDate=2007:08:17 14:16:51
-IPTC:DateCreated=2007:08:17
-IPTC:TimeCreated=14:16:51-05:00

5) Do Metadata -> Read Metadata from File

6) Observe "Date Time Original" and "Date Time Digitized" in the metadata panel: "Date Time Original" has changed to 8/17/07 2:16:51 PM, while "Date Time Digitized" remains 8/17/07 3:16:51 AM
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Dan Smith

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Posted 3 weeks ago

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Patrick Philippot

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Hi Dan,

The "Read metadata from file" command doesn't read the image file metadata. It reads the metadata from the XMP file and updates the LR catalog with these data. In the really version of LR, there was a command to refresh the metadata from the image file but it seems to have disappeared.

What you should try (with just one image to confirm the validity of the procedure) is to remove the image from the catalog and then add it back (make a backup of the XMP file before, just to be sure). The metadata will be read from the photo file and your edits re-read from the XMP file that shouldn't be deleted when you remove the image from the catalog.
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Patrick Philippot

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My comments are irrelevant. Please disregard.
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Patrick Philippot

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> What you should try (with just one image to confirm the validity
> of the procedure) is to remove the image from the catalog and
> then add it back

This could be tried, however.
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Dan Smith

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Hmm, strangely, when I add the file to another library (one that has never seen this photo before), I _still_ get the wrong digitized time: 8/17/07 3:16:51 AM.

This is surprising, because I can't find any instance of that time in the file. I searched everything dumped by ExifTool (invoked with the file name, no extra arguments), and the 3:16:51 time doesn't appear anywhere.

It must be somewhere in the file, but I don't know where, or how to change it...
(Edited)
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Patrick Philippot

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Interesting. Could you make a link to a sample file public so that I could test what my copy of LR is reading ?
(Edited)
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John R. Ellis, Champion

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You steps don't include changing IPTC:DigitalCreationDate and DigitalCreationTime, and most likely LR is setting its Date Time Digitized from them.

This may be correct behavior according to the Metadata Working Group's Guidelines for Handling Digital Metadata, the spec that generally guides LR's handling of metadata.  Whether an EXIF or IPTC field gets precedence depends on the presence of an IPTC checksum (see chapter 4).  But since many programs don't follow the MWG spec, in general it's best to either set all three corresponding fields in EXIF, XMP, and IPTC, or set one of the fields and delete the other two.  (EXIF fields are the most widely used.)
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John R. Ellis, Champion

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Aslo, the Metadata Working Group's Web site is down right now (http://www.metadataworkinggroup.org/), so you can't access their spec.  There's been little apparent activity with the MWG since they issued version 2 of their spec in 2010, so it's not surprising no one is minding the store. 
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John R. Ellis, Champion

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Also, I forgot that Exiftool now supports tag aliases that read and write EXIF, XMP, and IPTC fields in accordance with the MWG spec:
https://sno.phy.queensu.ca/~phil/exiftool/TagNames/MWG.html

So you can do this:
exiftool -mwg:createdate="2007:08:17 14:16:51" file

to set the corresponding EXIF, XMP, and IPTC fields to the same value in accordance with the spec.  
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Patrick Philippot

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Dan Smith

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I should add that I'm also setting time zone tags.
-EXIF:OffsetTime=-05:00
-EXIF:OffsetTimeOriginal=-05:00
-EXIF:OffsetTimeDigitized=-05:00

I had a theory that Lightroom was just displaying times in UTC, but, nope, the math doesn't check out. And I have the same problem if I adjust the digitized time by one second—change doesn't appear in Lightroom.

I'm not making use of any other time-related tags, and ExifTool doesn't report them being used. But I'll do some further experiments with IPTC and MWG prefixes and report back.
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John R. Ellis, Champion

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Upload the original file to Dropbox or similar and post the sharing link here.  
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John R. Ellis, Champion

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Also, when examining fields with Exiftool, use the switches "-a -G" to remove ambiguity about which fields you're viewing, e.g.
exiftool -a -G file
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Dan Smith

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Looks like the "-a" option was what I was missing—it reveals a hidden XMP tag:
-XMP:CreateDate=2007:08:17 03:16:51.00

Updating that tag fixes what I see in Lightroom.

Reading/writing the "mwg" tags seem to be the best way to consistently set all the relevant tags.

Thanks for the help!
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John R. Ellis, Champion

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Hmm, my reading of the spec indicates that LR should have preferred the fields in this order: IPTC, EXIF, XMP.  It may be that LR doesn't quite adhere to the spec, or I'm misunderstanding it. But this is a very obscure corner of the spec, and Adobe is hardly going to change the current behavior, given LR's focus on managing photos from digital cameras (which have the fields consistently set).

Using MWG: to set all three fields will avoid any ambiguity, of course.  Glad you got it resolved.