Panasonic Lumix LX100 II vs Panasonic Lumix S1R II: read noise comparison

The Panasonic Lumix LX100 II (Lumix DC-LX100M2) was measured at 25 ISO settings from ISO 100 to ISO 25600. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 0.97 DN, or 8.5 electrons at the sensor. From ISO 1600 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 12800 don't change analog gain (digital push). Full well at base ISO is about 34,593 electrons; unity gain is around ISO 880.

The Panasonic Lumix S1R II (Lumix DC-S1RM2) was measured at 29 ISO settings from ISO 80 to ISO 51200. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (80) read noise is 1.99 DN, or 8 electrons at the sensor. A second gain (dual gain) kicks in at ISO 400, cutting input-referred read noise by about 1.8 stop. From ISO 20000 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Full well at base ISO is about 64,192 electrons; unity gain is around ISO 320.