Nikon D7500 vs Nikon D80: read noise comparison

The Nikon D7500 was measured at 38 ISO settings from ISO 50 to ISO 1638400. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 1.39 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 1.1 stop. From ISO 2000 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 46,707 electrons; unity gain is around ISO 290.

The Nikon D80 was measured at 16 ISO settings from ISO 100 to ISO 3200. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 2.39 DN, or 15.2 electrons at the sensor. From ISO 100 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 640 don't change analog gain (digital push). Full well at base ISO is about 25,971 electrons; unity gain is around ISO 630.