Can't find photos taking up storage space

I backed up everything I had to an external hard drive and deleted almost all the files off my Mac, I even ran Onyx to clear out my caches in the Library folder. But when I go to "about this mac" it says I still have almost 4GB of photos, 1.5GB of audio and some left over video files (as well as 36.5GB of "Other" which I'm guessing is caches and plugins and stuff like that).

Forgive the question if it's amateurish, I'm not very computer savvy, but I can't think of where those photos and video could be hiding since I deleted practically everything. Any help is much appreciated.