Xiomi recently showed off a concept phone that can take full size Leica lenses.
The stills camera market is a difficult space to be in right now. With the ever increasing quality of smartphone cameras, the compact market is, well, not doing so well. The average smartphone can now obtain images that might have been the preserve of much more expensive and larger devices a few years back, so it's not really surprising that the number of people wanting to buy a separate camera is dwindling.
The big limitation with smartphones, however, is the limited lens choice. True, finding a smartphone that is equipped with multiple fixed lenses, and even limited optical zooms is becoming more common, but there's no truly customisable option out there.
Recently Xaomi showed off a concept smartphone, called the 12S Ultra Concept, which it developed in conjunction with Leica. The device never made it to market, but it shows a glimpse of what is possible when you combine a phone with the ability to use full size lenses.
In addition to the standard built in camera, the device features a 1-inch 50.3MP sensor that would take its images from swappable Leica M-Mount lenses. Only 10 units were ever produced, and it's unlikely to ever come to market, the reasons for which might be obvious.
The market for a smartphone that takes full size lenses would be incredibly small. Most users want convenience, and if you have to carry around bulky lenses with you, you might as well just pack a good DSLR or mirrorless camera. That said, it does show what can be done with a compact device, although the future of smartphone camera tech really lies with multiple built in lenses and computational photography.
H/T to Petapixel.