Switching from LIGHTROOM to PHOTOS, is there any way to 'import' captions, titles & other user-entered metadata

In images it is possible to use old IPTC metadata and new XMP metadata. Apps like GraphicConverter currently by default use both in sync but IPTC is being phased out. Adobe pushes XMP so your old Lightroom images might very well have XMP set which Photos can import (GPS, title, description, keywords -- dates are in EXIF).

You might check your images with GraphicConverter's browser -- if it sees the data you need you should be OK.

On the other hand, movie metadata is sadly not yet standardized. Adobe tries to push XMP there but Apple's apps ignore it and use Keys metadata instead.

With exiftool it is a breeze to convert metadata to another standard but there is some learning curve. GraphicConverter has similar options but I have always resorted to exiftool in metadata fine-tuning.

In Lightroom Classic, I select the files and use File>Export. The result is jpegs with metadata intact.

This is one of the selections in the Export dialog. You can also set format type and quality, etc.

baldoyler wrote:

JPEG rather than RAW. At least as far as I can see, up to now the RAW images I’ve imported into photos don’t appear to have the missing user input, captions and other information.

.jpg metadata is very much standard. But it is usually best to be cautious when inserting metadata to raw images because vendors might use proprietary info there and extra metadata might corrupt raw. So it might be better to insert metadata in .xmp sidecars instead injecting it to raw. That said, I dislike sidecars and have not experienced any ill effects inserting metadata to Canon .cr2 or .cr3 raw files. But I usually try to keep raw intact and insert metadata only to the exported .jpg (I rename both as YYYY-MMDD-hhmm-ss.* so .jpg carries metadata for both. So in case I re-edit raw I just copy metadata from the old .jpg to the re-edited .jpg).

.png and .webp images do not support as much metadata as .jpg in some apps but I have treated them in the very much same workflow as .jpg and Photos.app has been OK with them.

baldoyler wrote:

JPEG rather than RAW. At least as far as I can see, up to now the RAW images I’ve imported into photos don’t appear to have the missing user input, captions and other information.

Just to add to my previous reply. Inside Photos added metadata goes to the Photos database, not to the originals which Photos always keeps intact. You can export that edited metadata either by exporting as .jpeg or some other re-encoded codec, or in .xmp sidecars together with the originals.