TREN
Phase One P40+ read noise vs ISO
The Phase One P40+ was measured at 6 ISO settings from ISO 100 to ISO 3200. Values were derived by Bill Claff from DxOMark lab data.
At base ISO (100) read noise is 17.03 DN. From ISO 100 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise.
Phase One P40+ read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 100 | 17.030 | 4.09 |
| 200 | 30.910 | 4.95 |
| 400 | 62.683 | 5.97 |
| 800 | 127.116 | 6.99 |
| 1600 | 315.173 | 8.30 |
| 3200 | 596.344 | 9.22 |