When I transfer pictures from my camera to my mac, the pictures show up in both iPhoto and my downloads folder. Can I delete them from the downloads folder, or will this also remove them from iPhoto?
MacBook Pro, iOS 8.4
There is no "downloads" folder involved with iPhoto
There is a last download album - if that is what you are referencing then NO! - That is not a "place" and those are not duplicates - in iPhoto that is just one of many ways of viewing the photos in the library - if you remove them form last import then they are gone from the library and therefore from events, Photos, last "n" months, etc
LN
duplicate pictures in downloads and iPhoto
