Canon EOS R10 (ES) read noise vs ISO

The Canon EOS R10 (ES) was measured at 27 ISO settings from ISO 100 to ISO 51200. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 3.86 DN, or 8.2 electrons at the sensor. From ISO 6400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 32000 don't change analog gain (digital push). Full well at base ISO is about 33,823 electrons; unity gain is around ISO 210.