Is there a common subset of exif metadata tags for scanned photographs?

Question

I've recently been scanning a collection of photographs into jpeg files.

I know how to use tools such as exiftool to examine and change metadata tags. But while I'm easily able to learn the technical skills required, I've very little practical experience with the details of digital photography.

In particular, when I look for a list of tags that I could set on these scanned photographs, I'm overwhelmed by the results.

Is there a small subset of tags that would commonly be used for scanned photographs?

Answer 1

There's no subset of metadata that is specialized for scanned images, so you'll have to use standard tags, possibly re-purposing some for your own use.

Trying to figure out what tags to use based upon what exiftool can edit isn't the best way to go about it, as exiftool can edit thousands of obscure tags that don't get much everyday usage. You're best bet is to use something like Adobe Bridge (which is free) or a Digital Assets Manager (DAM) such as DigiKam (also free). They provide a graphical interface with all the standard tags, taking care of any differences between the various specs (IPTC IIM, IPTC Core/XMP, EXIF) behind the scenes so you don't need to try figure these things out.

I would suggest creating a text template for the details you want to embed, add a basic description to the top of that for each image, and put the whole thing in the Description. Keep the data in an easily parsable like Info: Details and on separate lines. That way, if you figure out a better solution later on, you'll be able to use exiftool to extract and move the data.

Answer 2

It really depends on why you are scanning photographs in the first place. I don't know your goals, and below is my solution for my, rather niche needs. Also, it is the solution of a person who likes programming as a hobby.

I am scanning/maintaining digital photos for genealogy/archival purposes. As such, I am mainly interested in who is depicted in the photo, where and when the photo was taken, where I got it from. In this case, the XMP face tags are most interesting, together with geotagging and various description tags. And I spent quite some time converting Picasa (which I used for automatic face recognition) and Flickr (which was used to ask relatives to tag faces) data to XMP tags.

However, I then concluded that storing information in photos is actually not a great idea:

• What happens if you discover that your meaningful tag in 1000 photos is invalid (e.g. a person you tagged with his name is actually a different person? or has a different name?)
• What if you were text-tagging photos made in London, UK with "London", only to find out that there are 5 more Londons in the US?
• When geo-tagging a photo, you actually hide ambiguitiy: is the coordinate you use the coordinate of the photographer, of the depicted object, or just a center or even an arbitrary point in the country in which the photo was taken? Geotagging is great if the camera records the GPS coordinate, but arguably not for scanned images.
• What happens if you scan a photo, tag it, then forget it, scan it again, tag it with something different (because you have new information), and then find the original file? You now have two files of the same object with possibly inconsistent tags.

Based on the above and also on the inability to find a good-for-my-needs software that could manipulate all these tags in a meaningful way (see also this question), I ended up with a very different approach. I am now assigning a UUID to each real (physical) object, and add tag Title=<uuid> to all scans of that object. The UUID is somehow attached to the object (I keep photos and documents in archival folders, and just put a sticker with UUID to individual sleeves/files). Then, I have a central database, in which I keep the metadata. Thus, I have only one storage for all meaninful data, and photo files contain only meaningless (random) UUID.

It also gives the necessary flexibility. E.g. a common source of confusion with "properly tagged" photos has been the disagreement between my relatives as to who was depicted in the image. I may not know the person, and two older people I ask give me two different names. With a separate custom database I do not have to choose, I simply store raw user comments, so the research history is fully preserved, including possible discussions and arguments, links to sources and cross-links.