WTF?! While it's long been said that flagship smartphones are making digital cameras obsolete, that statement has never been truer than with the Xiaomi 12S Ultra Concept. The phone has the unique feature of allowing users to attach an interchangeable Leica M lens to the rear of the device.

Developed in partnership with German camera giant Leica, the Xiaomi 12S Ultra Concept looks pretty much identical to the Xiaomi 12S Ultra---it was created alongside that flagship---but this version has a second, one-inch 50.3-megapixel sensor in the middle of the camera island.

The extra sensor, which is another Sony IMX989, is placed beneath a circular piece of sapphire glass that the attachable lenses cover. Installing one of the M-series Lecia lens modules, which range from f/1.4 to f/16, involves unscrewing the ring around the island and mounting it via an adapter.

Xiaomi writes that the 5G phone will come with features that include focus peaking, zebra lines, histogram, and 10-bit RAW shooting.

The 48-megapixel ultra-wide camera that had been positioned in the middle of the camera island has been moved to the same space that the 48-megapixel periscopic telephoto camera had occupied.

As the name suggests, the Xiaomi 12S Ultra Concept is still a concept phone, of course, so we don't know if it will ever make its way onto the market---only ten sample units have been made---but the amount of work Xiaomi appears to have put into its design suggests the company has its sights on a finished consumer version. Engadget writes that each sample cost around 300,000 yuan or about $41,210 to make, so expect them to be expensive.

About the closest thing we've seen to this concept is the Android-based Yongnuo mirrorless cameras (above) that have only been available in China. There was also the Samsung Galaxy Camera and Samsung Galaxy NX from many years ago. It'll be interesting to see if the Xiaomi 12S Ultra Concept offers a compelling mix of high-end digital camera and smartphone.