Canon EOS R6 Mark III (ES) vs Canon EOS R7 (EFCS): read noise comparison

The Canon EOS R6 Mark III (ES) was measured at 31 ISO settings from ISO 50 to ISO 102400. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 2.85 DN, or 13.8 electrons at the sensor. A second gain (dual gain) kicks in at ISO 800, cutting input-referred read noise by about 1.8 stop. From ISO 3200 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 77,289 electrons; unity gain is around ISO 490.

The Canon EOS R7 (EFCS) 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 2.46 DN. 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).