TREN
Sony a7 II read noise vs ISO
The Sony a7 II (ILCE-7M2) was measured at 28 ISO settings from ISO 50 to ISO 25600. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.
At base ISO (100) read noise is 1.24 DN, or 5.1 electrons at the sensor. From ISO 320 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 20000 don't change analog gain (digital push). Full well at base ISO is about 65,656 electrons; unity gain is around ISO 410.
Sony a7 II read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 50 | ○ 1.248 | 0.32 |
| 64 | ○ 1.395 | 0.48 |
| 80 | ○ 1.625 | 0.70 |
| 100 | 1.240 | 0.31 |
| 125 | 1.424 | 0.51 |
| 160 | 1.636 | 0.71 |
| 200 | 1.879 | 0.91 |
| 250 | 2.266 | 1.18 |
| 320 | 2.639 | 1.40 |
| 400 | 3.249 | 1.70 |
| 500 | 3.864 | 1.95 |
| 640 | 4.790 | 2.26 |
| 800 | 5.897 | 2.56 |
| 1000 | 7.362 | 2.88 |
| 1250 | 9.254 | 3.21 |
| 1600 | 11.551 | 3.53 |
| 2000 | 14.621 | 3.87 |
| 2500 | 18.379 | 4.20 |
| 3200 | 22.943 | 4.52 |
| 4000 | 29.041 | 4.86 |
| 5000 | 36.758 | 5.20 |
| 6400 | 46.206 | 5.53 |
| 8000 | 58.485 | 5.87 |
| 10000 | 73.517 | 6.20 |
| 12800 | 92.411 | 6.53 |
| 16000 | 116.162 | 6.86 |
| 20000 | 146.018 | 7.19 |
| 25600 | ▼ 149.086 | 7.22 |