TREN
Olympus OM-D E-M1X read noise vs ISO
The Olympus OM-D E-M1X was measured at 24 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 0.75 DN, or 3.9 electrons at the sensor. From ISO 2500 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Full well at base ISO is about 19,749 electrons; unity gain is around ISO 1030.
Olympus OM-D E-M1X read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 64 | ○ 0.889 | -0.17 |
| 100 | ○ 0.841 | -0.25 |
| 200 | 0.753 | -0.41 |
| 250 | 0.895 | -0.16 |
| 320 | 0.993 | -0.01 |
| 400 | 1.197 | 0.26 |
| 500 | 1.444 | 0.53 |
| 640 | 1.729 | 0.79 |
| 800 | 2.071 | 1.05 |
| 1000 | 2.395 | 1.26 |
| 1250 | 3.031 | 1.60 |
| 1600 | 3.605 | 1.85 |
| 2000 | 3.387 | 1.76 |
| 2500 | 4.084 | 2.03 |
| 3200 | 4.790 | 2.26 |
| 4000 | 5.897 | 2.56 |
| 5000 | 7.160 | 2.84 |
| 6400 | 9.318 | 3.22 |
| 8000 | 11.632 | 3.54 |
| 10000 | 14.929 | 3.90 |
| 12800 | 18.379 | 4.20 |
| 16000 | 23.588 | 4.56 |
| 20000 | 30.274 | 4.92 |
| 25600 | 37.014 | 5.21 |