TREN
FujiFilm X-A5 read noise vs ISO
The FujiFilm X-A5 was measured at 19 ISO settings from ISO 200 to ISO 12800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.
At base ISO (200) read noise is 2.16 DN, or 2.4 electrons at the sensor. From ISO 640 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 3200 don't change analog gain (digital push). Full well at base ISO is about 16,938 electrons; unity gain is around ISO 220.
FujiFilm X-A5 read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 200 | 2.158 | 1.11 |
| 250 | 2.549 | 1.35 |
| 320 | 3.138 | 1.65 |
| 400 | 3.811 | 1.93 |
| 500 | 4.563 | 2.19 |
| 640 | 5.657 | 2.50 |
| 800 | 6.869 | 2.78 |
| 1000 | 8.225 | 3.04 |
| 1250 | 10.267 | 3.36 |
| 1600 | 12.641 | 3.66 |
| 2000 | 15.671 | 3.97 |
| 2500 | 19.160 | 4.26 |
| 3200 | 24.084 | 4.59 |
| 4000 | ▲ 29.857 | 4.90 |
| 5000 | ▲ 37.792 | 5.24 |
| 6400 | ▲ 48.503 | 5.60 |
| 8000 | ▲ 60.548 | 5.92 |
| 10000 | ▲ 76.109 | 6.25 |
| 12800 | ▲ 97.006 | 6.60 |