iPhoto appears to be grabbing many multiples more space than is necessary to store a photo. I imported about 500 megs of JPGs already on my hard drive; my prefs are set so that iPhoto creates its own copies. I figured that I would simply delete the "originals" after the import was done and the net space would be about the same, except for the thumbnails. My hard drive free space shrunk by 5 gigs!!
I did a complete rebuild of the iPhoto library (opening with command-control) and did not notice a significant increase in free space.
I looked for invisible or visible large files on my entire computer and can't find anything to explain the lost free space.
Any suggestions appreciated. Thanks