AT&T today made the Denim system update available to the Nokia Lumia 1520. The update makes numerous changes to the behavior of the camera, including a faster shutter and 4K video capture, and also adds Live Folders and an updated Glance screen.
According to Microsoft, Lumia 1520 owners need to have 1GB of free internal storage in order to install the update, which can be downloaded and installed via WiFi. The update is free.