Can not free up storage space after deleting all photo
I have a iPhone5 with ios8.1. I deleted all photo and videos in my photo library to free up space. however, in usage it still shows the photo library used more than 6gb space. in "about" page of setting, it shows 800 photos and 70 videos in my iPhone. but I cannot find any photo in photo library, and not from iTunes or iPhoto by connecting to MAC. it bother me for a few weeks. does anyone have a solution?
Thanks
Ann
iPhone 5, iOS 8.1.1