Hi Cory, Sorry to be so long getting back to you. So I am using El Capitan Version 10.11.16 on iMac Mid 2207. There is plenty of space of space on the computer: 164.61 GB free of 249.2 GB. I attach an example of a photo with the head cut off. The photos at this point were taken with a digital camera. All iPhotos imported into Photos starting in 2016 are shown vertical and cannot be edited to appear horizontal. I wonder if the photos cut in half had too much digital information (too large) to fit into the Photos format. Sure enough, the Attach file box says that the screen shot photo I wanted to send you as example is too large to send. At the time of transfer I was running iPhoto version 7.1.5. I found an article that says you must have upgraded to iPhoto 9 before transfer to Photos or you are SOL.
https://discussions.apple.com/docs/DOC-8431 I bought the computer in 2007 with this version of iPhoto on it. Also have Time Machine backups going back to this point. Am I understanding that I could create another user, who has an entirely different computer. I could go back and restore the 2015 computer with iPhoto, upgrade to iPhoto 9. Would I be going to the app store as the original me who bought this computer in order to be allowed to upgrade? Then transfer the updated iPhoto version to Photos? Could this all go terribly wrong? If you believe this is worth trying, I would need very specific instructions. I think I might end up with duplicates, but that might be better than losing photos altogether. Or I can just delete the bad photos and consider it a lesson learned. I would like to sort all the photos before buying a later iMac to prevent another catastrophe. Thanks for advice. I won't be offended if you say to just let the too-large photos go.