I have a number of video/image files to which I added tags via Finder. I have now decided to use Lightroom Classic to catalogue these items. Can anyone advise me how to import the tags into LR converting said tags to keywords?
For photos, can't you just give it a try? I think importing will recognize the keywords/tags that you have already applied. (If it doesn't recognize the keywords/tags, then use the menu command File->Read Metadata from Files).
I don't think this will work for videos, I don't think LrC can handle external metadata for videos (but certainly give it a try anyway).
LR won't import the tags you've assigned in Finder -- they are stored in a way that few apps can access.
You could use the free Exiftool utility to copy the Finder tags into the standard photo metadata field that stores keywords and then import those photos into LR. This post gives a hint:
One thing not called out in that post is that for JPEGs and other non-raw file formats, LR expects to find the XMP metadata fields (including the one storing keywords) inside the files themselves. But for raws, LR will import the metadata from a .xmp sidecar. Google will reveal recipes about how to do the latter.
Exiftool is not for the faint of heart, and if you're not experienced with command-line scripting, I don't recommend trying it.
There might be other solutions, but I didn't find any in a casual Google search.
I just tried this on Windows 11, Lightroom Classic 11.4.1. I added a tag to a JPG photo using Windows Explorer, then imported the photo to Lightroom Classic, and the tag appears in the LrC keywords for this photo.
Of course, I don't know if this works on a Mac.
Those are not tags as used in MacOS.
OP, you would need to export those tags to a text file which then should be easily imported via Bridge or Lightroom. I'm not at my Macs and would have to take a look when i am, but I'm sure it is doable.
"I just tried this on Windows 11, Lightroom Classic 11.4.1. I added a tag to a JPG photo using Windows Explorer, then imported the photo to Lightroom Classic, and the tag appears in the LrC keywords for this photo."
The "Tags" field of the Properties > Details panel of Windows File Explorer stores the entered tags in the photo industry-standard keywords fields XMP:Subject and IPTC:Keywords, and LR will read them from there.
But Mac Finder "Tags", which can be applied to any file type and not just photos, are stored in Mac OS-specific fields ("extended attributes") which aren't stored in the files proper but in volume metadata. Most apps, including LR, are blissfully unaware of most extended attributes.
Apple has documentation for apps to read and write Finder tags, so Adobe could easily support this if they wanted to. But it would not be cross-platform.