Sony QX1 vs Sony RX10 III: read noise comparison

The Sony QX1 (ILCE-QX1) was measured at 23 ISO settings from ISO 100 to ISO 16000. This model has no measurement of its own; the Sony a5000, which uses the same sensor, is shown.

At base ISO (100) read noise is 2.57 DN, or 5.3 electrons at the sensor. From ISO 400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 10000 don't change analog gain (digital push). Full well at base ISO is about 32,589 electrons; unity gain is around ISO 210.

The Sony RX10 III (DSC-RX10M3) was measured at 24 ISO settings from ISO 64 to ISO 12800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 3.12 DN, or 3 electrons at the sensor. From ISO 6400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Full well at base ISO is about 14,868 electrons; unity gain is around ISO 100.