Canon EOS R5 C read noise vs ISO

The Canon EOS R5 C was measured at 30 ISO settings from ISO 50 to ISO 102400. This model has no measurement of its own; the Canon EOS R5, which uses the same sensor, is shown.

At base ISO (100) read noise is 1.33 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 2 stop. From ISO 1600 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 49,605 electrons; unity gain is around ISO 310.