More about migrating iPhoto library to Photos library on Ventura

In the new Photos library you will see the albums, the events will be converted to albums, the rating starts will be converted to keywords.

• The titles of the photos ans videos should be transferred.
• The locations may have different names, but be the same place.
• Most named faces have been missing. I suggest to save the names in the people album as a keyword showing the name.
• The date and time might have a time shift. Not all photos have been converted with the correct timezone applied.
• The smart albums were a mess, because Photos does not have the same smart rules as the smart albums in Photos.
• The descriptions of the albums have been missing.

The adjustments have been transferred as the previews. In Photo we can no longer revert the iPhoto adjustments individually. If you have been using Aperture together with Photos to reduce the size of the previews, you will have to repeat the edits in Photos to get high quality previews.

How did you add the notes in iPhoto? The Tites and descriptions I added to my photos in iPhoto 9 have been transferred to the Photos Library and were visible.

But it has been ten years since I migrated from iPhoto to Photos. The Photos version I am having on my oldest Mac (Photos 4 on macOS 10.14 Mojave ) is very different from Photos macOS 10.13 High Sierra. Photos has been become much more usable since the version on High Sierra. It is hard to remember details.

The best you can do is really to create a Photos Library from one of your iPhoto Libraries on your High Sierra Mac and then compare the iPhoto Version to the Photos version, side-by-side as Yer_Man recommended. This will make it. easier to fix any problems than on your new Mac, where you can no longer run iPhoto and you can no longer migrate an iPhoto library as a library.

A second problem you may encounter are videos and image files in a legacy format. Since macOS 10.15 Catalina the system does no longer support 32-bit applications. And Apple has removed some of the iLife frameworks from the system, that supported older video and image formats. If you are having media files in your iPhoto Libraries, that are no longer supported on your new Mac, they may be causing problem. You should convert all media, that can no longer bemused on your new Mac on your old Mac, where you can still open them and export them in a new format.

Rather a long time since I did this, so the best I can suggest is try it and see. The good thing is your iPhoto library is unaffected by the process.