El Capitan and Photo
How do you remove duplicate pictures and videos from Photo
Mac Pro, OS X El Capitan (10.11.3), Photo (and not iPhoto)
Generally Photos is good about not getting duplicates - the most common way is user error importing multiple times like iTunes Sync and MyPhotoStream as one example
getting rid of them is either manual or using one of the user tested safe dupicate identification programs
PhotoSweeper for Photos
Duplicate Annihilator for Photos
LN