TREN
Olympus System OM-5 Mark II (ES) read noise vs ISO
The Olympus System OM-5 Mark II (ES) 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 0.72 DN. From ISO 8000 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise.
Olympus System OM-5 Mark II (ES) read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 64 | ○ 0.818 | -0.29 |
| 100 | ○ 0.753 | -0.41 |
| 200 | 0.722 | -0.47 |
| 250 | 0.818 | -0.29 |
| 320 | 0.946 | -0.08 |
| 400 | 1.117 | 0.16 |
| 500 | 1.320 | 0.40 |
| 640 | 1.591 | 0.67 |
| 800 | 1.905 | 0.93 |
| 1000 | 2.329 | 1.22 |
| 1250 | 2.809 | 1.49 |
| 1600 | 3.411 | 1.77 |
| 2000 | 4.141 | 2.05 |
| 2500 | 4.959 | 2.31 |
| 3200 | 6.190 | 2.63 |
| 4000 | 7.890 | 2.98 |
| 5000 | 9.987 | 3.32 |
| 6400 | 12.467 | 3.64 |
| 8000 | 8.574 | 3.10 |
| 10000 | 11.004 | 3.46 |
| 12800 | 14.026 | 3.81 |
| 16000 | 17.148 | 4.10 |
| 20000 | 22.009 | 4.46 |
| 25600 | 26.909 | 4.75 |