Why can't I see my photos in finder? When I search for photos in finder I can see just Photo Booth's photos:  



But I have a lof of pictures in Photos app, why can't I see them?

Update

The option "use as system photo library" (in Italian: "usa come libreria foto di sistema") is disabled.
It seems like you might need to open the Photos app, and within Preferences choose "Use as System Photo Library"...

Source: https://discussions.apple.com/message/28138885#28138885

However if this doesn't work it would suggest something on your Mac isn't setup right and you should try backing up your data and reinstalling by following these instructions.