Sony DSC-RX1 vs Sony DSC-RX100: read noise comparison

The Sony DSC-RX1 was measured at 12 ISO settings from ISO 50 to ISO 25600. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 1.13 DN, or 4.9 electrons at the sensor. From ISO 400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Full well at base ISO is about 68,744 electrons; unity gain is around ISO 430.

The Sony DSC-RX100 was measured at 9 ISO settings from ISO 80 to ISO 6400. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (125) read noise is 3.81 DN, or 10.1 electrons at the sensor. From ISO 800 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 3200 don't change analog gain (digital push). Full well at base ISO is about 40,970 electrons; unity gain is around ISO 330.