Beware with photo deletion in Windows file explorer. Don't loose your last trip pictures like I did.

[Francisco Amestoy]

So, this is it, pretty straight. If you connect your 1020 to the Pc, it will recognize it as an MTP device and show all your photos in the Camera Roll.

I had it configured to save JPG+DNG photos, so I can see both file types in the folder. I searched for ".jpg so Windows Explorer show me all the files with that extension. Then, I did "select all" and "delete", permanently deleting all the low resolution photos.

The big surprise came when I removed the search term in Explorer. All DNG were visible, but when I tried to copy to pc, some unknown error came out. Unplugged the phone, plugged it again and the camera roll was empty. Also, in the Gallery app, no more photos.

Did a couple of tests taking some pictures, and then deleting the jpg from inside the phone, and yup. If you delete the low res pics from the phone, it will also delete the DNG (high res) ones, so BE CAREFUL. Dont loose your last honeymoon trip photos like I did.

By the way, enable the Skydrive auto backup of the photos. Didn't have it on, since I thought it was impossible to get anything going wrong, and believe me, I regret it.

Kind regards

 

[Dietrich Cleijne]

I've had almost the same issue with photo's taken with my previous Lumia the 920.
One day duplicate images started to show up in the gallery of the phone, so when i had the time i started deleting the duplicates.
Luckily enough i had the auto-upload to skydrive on, because i deleted the complete picture, they weren't duplicates.
Most of the pictures were already saved to skydrive (Onedrive), but i lost a few.

 

[Francisco Amestoy]

I've had almost the same issue with photo's taken with my previous Lumia the 920.
One day duplicate images started to show up in the gallery of the phone, so when i had the time i started deleting the duplicates.
Luckily enough i had the auto-upload to skydrive on, because i deleted the complete picture, they weren't duplicates.
Most of the pictures were already saved to skydrive (Onedrive), but i lost a few.

Although the symptoms were different, I think your problem was similar. Maybe caused by the MTP protocol?