Help with Mac Photos.

[PabloSRT8]

Hi, Ill try to explain whats going on.

long story:

I have been using iPhoto since MacOS Puma.
Every year or so I would upgrade my mac or my mac hard drive.
Since 2002 I've been through many of them and it seems that since then, I ended up with missing photos.
I saved pretty much every iPhoto or Photo's library just in case.
I have all of them, in 8 hard drives, of curse they all contain repeats:
for example one library might be 2002 to 2003 and next library might be 2002 to 2005 and the next 2002 to 2007 etc...
I can tell that my latest library running of an 8gb hard drive (2002 to 2017) is missing photos.
I have on this library about 120k family photos, but I can tell that some are missing, like my daughters 5th birthday which I found on another library on a different hard drive that somehow never crossed over when I upgraded macs.

short story:

What is the safest way to add to current Photo app library, photos from older libraries?
(I don't know where they are, I don't want to end up with duplicates, I don't want to miss any like apparently I have done in the past)

 

[mikzn]

Have you tried PowerPhotos ? or iPhoto Library Manager ?

both apps are great to help manage and copy multiple pictures from multiple libraries to other libraries.