TREN
Canon EOS 5DS R read noise vs ISO
The Canon EOS 5DS R was measured at 21 ISO settings from ISO 50 to ISO 12800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.
At base ISO (100) read noise is 5.62 DN, or 13.1 electrons at the sensor. From ISO 3200 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 6400 don't change analog gain (digital push). Full well at base ISO is about 33,406 electrons; unity gain is around ISO 230.
Canon EOS 5DS R read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 50 | ○ 5.502 | 2.46 |
| 100 | 5.618 | 2.49 |
| 125 | 5.696 | 2.51 |
| 160 | 5.776 | 2.53 |
| 200 | 5.979 | 2.58 |
| 250 | 6.190 | 2.63 |
| 320 | 6.589 | 2.72 |
| 400 | 7.013 | 2.81 |
| 500 | 7.568 | 2.92 |
| 640 | 8.398 | 3.07 |
| 800 | 9.514 | 3.25 |
| 1000 | 11.236 | 3.49 |
| 1250 | 13.086 | 3.71 |
| 1600 | 15.671 | 3.97 |
| 2000 | 19.160 | 4.26 |
| 2500 | 22.316 | 4.48 |
| 3200 | 26.538 | 4.73 |
| 4000 | 33.359 | 5.06 |
| 5000 | 38.319 | 5.26 |
| 6400 | 45.887 | 5.52 |
| 12800 | ○ 90.510 | 6.50 |