iOS 10.3.1 - Apple iPhone - Photos app shows 295 images; none found on device internal storage I am using iOS 10.3.1 on iPhone 5S.

When I connect to my Windows 10 PC using USB and view the device in Windows Explorer, I can navigate to the iPhone\Internal Storage\DCIM\ folder - which is empty (I recently moved all my other photos onto hard disk).

When I open Photos app on the iPhone, I see 295 images.

They all appear in "My Albums" in the album "iPhone".

I do not have the option to delete the image. When I tap tools I see "This photo is not editable. Do you want to duplicate it and edit a copy?" with the option to 'Duplicate and Edit'.

Is there any way to retrieve these images via Windows Explorer interface? Must I manually 'Duplicate and Edit' all 295 images in order to have a copy to backup via Windows Explorer file system?

I am trying to backup all images from the device before I reset to factory original settings and list for sale.
I have no explanation for how the photos came to be read-only on the device, and hidden from the internal file system, but the solution to make a backup was:

On the device, navigate to the album. 

Select All images, then choose 'Duplicate to Edit' which places copies into Camera Roll. 

Once the duplicates are created, any of the usual methods for backup worked.

In my case, I could plug in with USB cord to my Windows PC, and transfer using Windows Explorer by navigating to iPhone\Internal Storage\DCIM\XXXX.