Panasonic Lumix DMC-CM1 was, for years, the smartphone with the largest camera sensor.

It is also the only smartphone that takes any external lens (37mm or any other with a step ring) like any other dedicated camera.

The combination of an f/2.8 lens and 1 inch sensor gave it a hitherto unprecedented ability for (unsimulated) shallow depth of field.

Forbes reserved judgement on the image quality given review samples were not available, writing "it remains to be seen whether a 1-inch sensor and Leica lens is enough to elevate the image quality of DMC-CM1 sufficiently high above the best smartphones".

[1] It is equipped with manual camera controls and allows for a maximum light sensitivity of ISO 25600.