Hasselblad H4D-50 vs Hasselblad H6D-100c: read noise comparison

The Hasselblad H4D-50 was measured at 5 ISO settings from ISO 50 to ISO 800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

The Hasselblad H6D-100c was measured at 9 ISO settings from ISO 64 to ISO 12800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (64) read noise is 3.07 DN, or 2.2 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 3200 don't change analog gain (digital push). Full well at base ISO is about 45,957 electrons; unity gain is around ISO 40.