TREN
Pentax Q7 read noise vs ISO
The Pentax Q7 was measured at 22 ISO settings from ISO 100 to ISO 12800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.
At base ISO (100) read noise is 1.27 DN, or 3.2 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 10,402 electrons; unity gain is around ISO 250.
Pentax Q7 read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 100 | 1.266 | 0.34 |
| 125 | 1.505 | 0.59 |
| 160 | 1.803 | 0.85 |
| 200 | 2.173 | 1.12 |
| 250 | 2.585 | 1.37 |
| 320 | 3.074 | 1.62 |
| 400 | 3.655 | 1.87 |
| 500 | 4.532 | 2.18 |
| 640 | 5.352 | 2.42 |
| 800 | 6.409 | 2.68 |
| 1000 | 7.516 | 2.91 |
| 1250 | 8.877 | 3.15 |
| 1600 | ▼ 10.629 | 3.41 |
| 2000 | ▼ 12.467 | 3.64 |
| 2500 | ▼ 15.889 | 3.99 |
| 3200 | ▼ 19.427 | 4.28 |
| 4000 | ▼ 23.752 | 4.57 |
| 5000 | ▼ 29.243 | 4.87 |
| 6400 | ▼ 35.753 | 5.16 |
| 8000 | ▼ 44.632 | 5.48 |
| 10000 | ▼ 57.680 | 5.85 |
| 12800 | ▼ 75.061 | 6.23 |