Using the Find Duplicates feature in PowerPhotos consists of three main steps.
Searching for duplicates The first step is to tell PowerPhotos what libraries you would like to search for duplicate photos, and how you would like it to compare photos to determine whether they are duplicates or not. You can read about this step in “Starting the duplicate finding process”. Once you start the duplicate finding process, PowerPhotos will perform an analysis of your photos and try to determine which photos are duplicates of each other. The result of the analysis is a list of duplicate groups. Each duplicate group contains two or more photos which have been identified as duplicates of one another. These groups will be shown to you in PowerPhotos’ duplicate browser.
Choosing keepers Next, PowerPhotos will choose a keeper from each duplicate group. You can customize how keepers are chosen from each duplicate group by choosing a duplicate rule, which will look at various attributes of the duplicate photos and choose one of them based on those attributes. A bunch of built-in duplicate rules are included with PowerPhotos, or you can create your own custom duplicate rule. You can read about this step in “Choosing keepers with duplicate rules”.
Trashing duplicates After choosing which photo(s) you want to keep from each group, the rest will be marked to be trashed. You can read about this step in “Deleting your duplicate photos”.