How to store film camera metadata in scanned images

[grafton84]

Perhaps this has been asked before; the most relevant posts were about custom metadata.

Suppose I want to store image data similar to what digital cameras store, but for scanned photos or negatives. The scanned image EXIF data considers the scanner the 'camera', so where else might I put that information? For example, the camera, lens, shutter speed, aperture, frame number, etc...

I'm curious what others are doing or might recommend short of creating custom metadata fields which may or may not write or persist properly (I use TIFF files for scans).

Rob...

[Mario]

XMP has all the tags you need for that. That's where the information should go.
If your scanned images have an (even rudimentary) EXIF record, IMatch also migrates the XMP data back to EXIF on write-back.
Which makes the data accessible even for applications which only know about EXIF.

Pro Tip: Create your own Metadata Panel layout which contains all the tags you want to fill (lens, camera, date and time, ...).
See: Metadata Panel Layouts
This way you have all the info to fill in one place.

Pro Tip 2: Use Metadata Templates to fill in common data or data that is the same for all scans (...in a set).
This saves you tons of time.

[mastodon]

There was a topic about this, maybe it helps you.

[Mario]

Thanks for the link. I did not remember...

Dealing with scans can be easy - or hard.
If you don't get too technical, usually all that is needed is the date the original image was created (date subject created) and the scan date. This puts the content in the proper place in your timeline.
If you also need (!) to record technical shooting information, XMP make/model, lens shutter speed, aperture are the tags to fill.
But I would give this a good think. Is this really needed? For family photos etc., this is usually not the case. For library or historical purposes, maybe.

[grafton84]

If you also need (!) to record technical shooting information, XMP make/model, lens shutter speed, aperture are the tags to fill.

If I replace the scanner make/model with the camera make/model, am I losing that information?

Rob...

[Mario]

There is only one official EXIF/XMP make model.
Decide what's more important for you and place that into these tags.
You can always record the scanner model in another tag or the description, like "scanned with Brand Scanner".

[grafton84]

There was a topic about this, maybe it helps you.

Thanks for the link, very helpful; lots of options...

Rob...

[grafton84]

• Well, the camera make/model doesn't write back to the TIFF file. It keeps reverting back to the scanner make/model.
• Shutter speed, aperture and lens are indicated as read-only, can't edit them.
• ISO says it's mapped to an XMP field and can't be edited directly.

So much for using the built-in XMP camera data fields. Anyone else able to edit these fields successfully?

BTW, this is mostly for new film images where I know/have this information and want to preserve it.

Rob...

[Mario]

2. and 3. You cannot edit EXIF metadata tags directly. You edit the corresponding XMP tags. And IMatch then maps them back to the native EXIF on write-back.

You also need to input the data in the correct format. By default the tags in the Metadata Panel use the formatted value so you need to input things like Apertue as 5.6 and Shutter Speed as 1/123 - else ExifTool may reject your values during write-back. You can also display the raw (numerical) value in your layout, and input numbers instead.
Keep in mind that it is highly unusual to manually create or edit EXIF metadata. This metadata format has been designed for cameras, not for humans.

1. ExifTool may not allow to change the make/model , because this is very important data used by many image editors to apply camera-specific settings.

2. Lens is especially difficult, because Lens is not a plain text field for most make/model combinations. Lens data is stored in various ways, usually in numeric values, and ExifTool has to use internal lookup tables to map these numbers to a "lens name" miraculously, and back. You need to take great care what you input there.

See, for example: https://exiftool.org/forum/index.php?topic=7423.0

I used XMP tags successfully:

XMP::tiff\Make\Make
XMP::tiff\Model\Model
XMP::exif\ShutterSpeedValue\ShutterSpeedValue
XMP::exif\ApertureValue\ApertureValue
XMP::exif\ISOSpeedRatings\ISO

[grafton84]

2. and 3. You cannot edit EXIF metadata tags directly. You edit the corresponding XMP tags. And IMatch then maps them back to the native EXIF on write-back.

Sorry for being dense, but I don't know know what this means. How do you edit corresponding XMP tags other than in the Metadata panel?

[Mario]

This is just one of the default Metadata Panel layouts.
Camera Data shows native EXIF data from the image. It cannot be modified directly, because it is mapped to XMP (and back, during write back).
Hence this data is for looking only, the lock shows that you cannot edit it.

I did list the XMP tags above you can use. And linked to the section in the IMatch help which explains how to create your own Metadata Panel layout.

As I said, adding/modifying the ISO, Aperture and even the make/model and lens is highly unusual. This data is usually written by the camera or recording device only.
Hence you need to be prepared to do some extra steps, like creating a custom Metadata Panel layout which shows the XMP tags corresponding to the EXIF tags you want to add/modify.
Then you can see and edit the data and IMatch does the rest. Keep in mind the cautions I have mentioned above.

[grafton84]

OK, got it and warnings duly noted. As proof of concept, I edited XMP tags in a small set of files, wrote back to files, then imported to Lightroom to see what would come over. Everything was as expected. Thanks again for the clarification.

Rob...