The full-frame L-mount camera is the first to use a 44MP BSI CMOS sensor that reads out quickly enough to realize 40fps image capture and 8K video.

The S1R II has a newly designed, much more compact body that is almost identical to the Lumix S5 II, which measures 134.3 x 102.3 x 91.8mm and weighs 712g / 1.57 lb body only. This does mean that the the large status LCD on top of the S1R which was useful for quickly checking the camera's key settings has been removed on the newer model.

For photographers wanting more than 44.3-megapixels of resolution, the S1RII offers a handheld high-resolution mode that can capture still images at 177-megapixels by shifting the sensor half a pixel and capturing and merging multiple exposures.