DJI Phantom 4 vs DJI ZenMuse X7: read noise comparison

The DJI Phantom 4 was measured at 4 ISO settings from ISO 100 to ISO 800. Values were derived by Bill Claff from DxOMark lab data.

At base ISO (100) read noise is 8.17 DN. From ISO 400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise.

The DJI ZenMuse X7 was measured at 9 ISO settings from ISO 100 to ISO 25600. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 6.15 DN, or 5.8 electrons at the sensor. From ISO 800 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 58,247 electrons; unity gain is around ISO 90.