Microsoft said last month that once the Nokia Lumia 1020 received Windows 10 Mobile, users would be able to download the Lumia Camera app directly from the Windows Store. Unlike Microsoft Camera, the Lumia Camera app gives Lumia 1020 users support for DNG RAW files. Interestingly, while the app is not supposed to work with other Lumia devices, there have been reports from users of the Nokia Lumia 535 and Microsoft Lumia 640 that Lumia Camera has worked on their phones.
It would make sense that the app works on the Lumia 1020, since the phone is a camera-centric model sporting a 41MP rear camera, with OIS. The camera uses Zeiss optics. There is both a Xenon flash, and an LED flash on board.
Nokia Lumia 1020 owners can download and install Lumia Camera for free from the Windows Store.