I have completely deleted all photos in all categories from my iPad 3 (16G iOS 7) but my settings continue to state that I still have 3.5G "used" (camera roll) in the Photos/camera app. I have no idea where/what these photos are and how to get rid of them. The management tool in i tunes when sync'ed with my iPad gives the following data. Apps: 2.45G Documents/data 1.25G Other 5.05G and 4.47G free.
- Go to Settings > General > Date & Time
- Untoggle "Set Automatically"
- Manually set the date a year or two in the past
- Open "Photos"
- Select "Albums"
- If, like me, you had already cleared out everything from the Camera Roll and "Recently Deleted" folder, you'll smile to see that your "Recently Deleted" folder now has thousands of images back. Those are your phantom photos
- Open it, "Select" and start deleting
- Return to "Date & Time" and fix your clock
- Now, go back into Settings > General > Usage > Storage > Manage Storage. You'll notice your Photo & Camera is empty if you deleted everything
Via the official Apple forums.
The iPad/iPhone might be saving cache/meta data to the device (which helps it to load images quicker). It will not show you this via the user interface.
You can delete it by using iexplorer (which is awesome).
Plug in your iPad/iPhone device Open the program (windows or Mac) Click on media The delete "PhotoData", "Photo StreamsData".
You should only do this if you have already removed all your photos from the device and backed them up and not concerned about losing anything.
Firstly, be aware that the phone can sometimes take a while to update free space after deleting large items. I have often wondered whether iOS is making the user experience a bit 'nicer' by reporting the item deleted instantly, while doing the actual deleting in the background. Or perhaps its just the time taken to update databases used to record/report used/free space. In any case, try giving it a few minutes (maybe an hour) and see if its 'settled down'.
Next up, in the Photos app, check the albums 'tab'. Is the camera roll reporting entirely empty? Are there any other albums? A 'full' Photo Stream (1000 photos) might take 1-1.5 GB, the photos in the camera roll (presumably 0) are perhaps 2MB each (depends on device). You can check these usage in the Settings app (General -> Usage -> Photos & Camera).
Finally, plug the phone into your computer, and open up an app like Apple's Image Capture or whatever you use on Windows/Linux to import photos from a camera. Check that there's actually no photos in the 'camera' that is your iPad. After clearing out my phone, I found a bunch of small, unreadable movie files and a few photos left over in this app. I don't know how or why, given the iPhone wasn't showing them, but they were clearly taking up space. You may have somehow ended up with a lot of these.
If the you cannot delete those photo on iPad, use a third party software like iFunBox to delete all photo data on computer, this will work and without the need of Jailbreak. Sometime iPad/iPhone take some time to delete data, like when I delete a huge game, the usage setting will show the app is deleted by it is actually still erasing the data in the background.