Sony a500 vs Sony a5000: read noise comparison

The Sony a500 (DSLR-A500) was measured at 7 ISO settings from ISO 200 to ISO 12800. Values were derived by Bill Claff from DxOMark lab data.

At base ISO (200) read noise is 1.58 DN. From ISO 1600 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise.

The Sony a5000 (ILCE-5000) was measured at 23 ISO settings from ISO 100 to ISO 16000. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

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.