i recently shot 191 Raw files taking up about 2.0 gig of space and loaded to iPhoto. I went to back up to a DVD and was informed the 191 photos would not fit on the DVD and i needed about 6 gig to back them up. i exported them to a folder on the desktop and i was back to my 2 gig. Does iPhoto really increase the storage needed by 300%? What's up with this?