TREN
Olympus System OM-5 read noise vs ISO
The Olympus System OM-5 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 0.74 DN, or 4.1 electrons at the sensor. From ISO 2000 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Full well at base ISO is about 21,203 electrons; unity gain is around ISO 1100.
Olympus System OM-5 read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 64 | ○ 0.841 | -0.25 |
| 100 | ○ 0.763 | -0.39 |
| 200 | 0.742 | -0.43 |
| 250 | 0.835 | -0.26 |
| 320 | 0.953 | -0.07 |
| 400 | 1.125 | 0.17 |
| 500 | 1.347 | 0.43 |
| 640 | 1.569 | 0.65 |
| 800 | 1.919 | 0.94 |
| 1000 | 2.297 | 1.20 |
| 1250 | 2.751 | 1.46 |
| 1600 | 3.340 | 1.74 |
| 2000 | 3.095 | 1.63 |
| 2500 | 3.655 | 1.87 |
| 3200 | 4.438 | 2.15 |
| 4000 | 5.502 | 2.46 |
| 5000 | 6.589 | 2.72 |
| 6400 | 8.694 | 3.12 |
| 8000 | 10.556 | 3.40 |
| 10000 | 13.269 | 3.73 |
| 12800 | 16.795 | 4.07 |
| 16000 | 21.407 | 4.42 |
| 20000 | 26.723 | 4.74 |
| 25600 | 33.825 | 5.08 |