Nikon Z 5 vs Nikon Z 50II: read noise comparison

The Nikon Z 5 was measured at 34 ISO settings from ISO 50 to ISO 102400. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 0.99 DN, or 4.4 electrons at the sensor. From ISO 10000 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 69,219 electrons; unity gain is around ISO 450.

The Nikon Z 50II was measured at 32 ISO settings from ISO 100 to ISO 204800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 1.55 DN, or 4.1 electrons at the sensor. A second gain (dual gain) kicks in at ISO 400, cutting input-referred read noise by about 0.9 stop. From ISO 5000 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 41,135 electrons; unity gain is around ISO 270.