Nikon D100 vs Nikon D1X: read noise comparison

The Nikon D100 was measured at 12 ISO settings from ISO 200 to ISO 6400. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (200) read noise is 2.73 DN, or 16 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 1600 don't change analog gain (digital push). Full well at base ISO is about 23,964 electrons; unity gain is around ISO 1170.

The Nikon D1X was measured at 11 ISO settings from ISO 125 to ISO 3200. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (125) read noise is 2.17 DN, or 17 electrons at the sensor. From ISO 160 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 800 don't change analog gain (digital push). Full well at base ISO is about 32,107 electrons; unity gain is around ISO 980.