TREN
Olympus OM-D E-M1 Mark II read noise vs ISO
The Olympus OM-D E-M1 Mark II was measured at 23 ISO settings from ISO 64 to ISO 25600. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.
At base ISO (200) read noise is 0.86 DN, or 7.2 electrons at the sensor. From ISO 3200 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 12800 don't change analog gain (digital push). Full well at base ISO is about 31,816 electrons; unity gain is around ISO 1660.
Olympus OM-D E-M1 Mark II read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 64 | ○ 0.853 | -0.23 |
| 200 | 0.865 | -0.21 |
| 250 | 0.702 | -0.51 |
| 320 | 0.801 | -0.32 |
| 400 | 0.927 | -0.11 |
| 500 | 1.057 | 0.08 |
| 640 | 1.292 | 0.37 |
| 800 | 1.548 | 0.63 |
| 1000 | 1.828 | 0.87 |
| 1250 | 2.204 | 1.14 |
| 1600 | 2.603 | 1.38 |
| 2000 | 2.445 | 1.29 |
| 2500 | 2.990 | 1.58 |
| 3200 | 3.555 | 1.83 |
| 4000 | 4.317 | 2.11 |
| 5000 | 5.278 | 2.40 |
| 6400 | 6.233 | 2.64 |
| 8000 | 7.890 | 2.98 |
| 10000 | 9.987 | 3.32 |
| 12800 | 12.295 | 3.62 |
| 16000 | ○ 16.111 | 4.01 |
| 20000 | ○ 19.562 | 4.29 |
| 25600 | ○ 25.281 | 4.66 |