Circa date created

[alanterra]

Hi

There is an XMP field called "Circa Date Created" that I am trying to set. Can you help me understand if exiftool can do this, and if I am formatting the command correctly.

The IPTC Photometadata spec (Oct 2016, p. 50) says "XMP namespace, Iptc4xmpExt", "XMP property id, AOCircaDateCreated", "XMP Value Type, Text", so I am using this command

% exiftool -XMP-Iptc4xmpExt:AOCircaDateCreated='1958' file.tif

and I get the response

Warning: Tag 'AOCircaDateCreated' does not exist
Nothing to do.

What am I doing wrong?

[Stephen Marsh]

I looked at a different tag and found that it was written as:

XMP-iptcExt

not XMP-Iptc4xmpExt

However this did not seem to help...

I even tried a .config file as this may be considered as a custom tag, however no luck there either!

So let's see what others have to say!

[StarGeek]

With exiftool ver 10.36, this works
exiftool -CircaDateCreated=Stuff FileOrDir

According to the XMP tag listing, it will accept a string and isn't limited to a date.

[Stephen Marsh]

Ah, I'm on 10.25 and I get the same error...

[StarGeek]

Now AOCircaDateCreated is different from CircaDateCreated.  AOCircaDateCreated is part of the ArtworkOrObjectDetails Structure and would need to be formatted with the -struct option and probably data for the other parts of the structure.

The question is whether CircaDateCreated as mentioned in the title or AOCircaDateCreated as mentioned in the post is the desired tag to be written to.

[alanterra]

Thanks, StarGeek. I do want CircaDateCreated not AOCircaDateCreated. I'll make sure that my version is up to date, and give "-CircaDateCreated=" a try.

[alanterra]

So, I asked over at ControlledVocabulary (Yahoo group) what the story is regarding AOCircaDateCreated vs. CircaDateCreated and received what I think is the definitive answer. David Riecks said:

"Phil Harvey responded early this morning with the answer. As it turns out, this is a field described within an IPTC specification. However it's not from the ones you are likely viewing. That's because Phil pulled this from the recently released IPTC Video Metadata Hub recommendation, rather than the Photo Metadata specifications.

"For those who are unfamiliar, you can access and overview of Video Metadata Hub at: https://iptc.org/standards/video-metadata-hub/

"The Final Draft (#4) showing all the fields and details can be found in the following Google doc: https://iptc.org/videometadata-draft4

"I think an argument could be made to make this field part of any revision/updates to the IPTC Photo Metadata specification, so I'll propose that to the working group."

Honestly, trying to figure out photo metadata just makes my head ache. All I wanted was a way of saying "I think that this photo was made around 1928", and I end up going down a rathole of competing standards. And, regardless, my software of choice, Lightroom, doesn't support any of these fields.