TREN
Phase One P45+ read noise vs ISO
The Phase One P45+ was measured at 5 ISO settings from ISO 64 to ISO 800. Values were derived by Bill Claff from DxOMark lab data.
At base ISO (64) read noise is 18.13 DN. From ISO 64 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise.
Phase One P45+ read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 64 | 18.126 | 4.18 |
| 100 | 42.518 | 5.41 |
| 200 | 85.036 | 6.41 |
| 400 | 170.072 | 7.41 |
| 800 | 340.144 | 8.41 |