TREN
Phase One IQ3 80MP read noise vs ISO
The Phase One IQ3 80MP was measured at 7 ISO settings from ISO 50 to ISO 3200. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.
At base ISO (50) read noise is 20.25 DN. A second gain (dual gain) kicks in at ISO 1600, cutting input-referred read noise by about 1.5 stop. From ISO 1600 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise.
Phase One IQ3 80MP read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 50 | 20.252 | 4.34 |
| 100 | 20.252 | 4.34 |
| 200 | 30.484 | 4.93 |
| 400 | 54.948 | 5.78 |
| 800 | 107.635 | 6.75 |
| 1600 | 78.793 | 6.30 |
| 3200 | 150.123 | 7.23 |