Panasonic Lumix S1 II vs Panasonic Lumix S5 IIX: read noise comparison

The Panasonic Lumix S1 II (Lumix DC-S1M2) was measured at 37 ISO settings from ISO 50 to ISO 204800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 0.67 DN, or 3.3 electrons at the sensor. From ISO 20000 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 51200 don't change analog gain (digital push). Full well at base ISO is about 78,328 electrons; unity gain is around ISO 490.

The Panasonic Lumix S5 IIX (Lumix DC-S5M2X) was measured at 37 ISO settings from ISO 50 to ISO 204800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 1.16 DN, or 6 electrons at the sensor. A second gain (dual gain) kicks in at ISO 640, cutting input-referred read noise by about 1.7 stop. From ISO 16000 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 51200 don't change analog gain (digital push). Full well at base ISO is about 81,471 electrons; unity gain is around ISO 510.