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Canon PowerShot G7 X Mark II read noise vs ISO
The Canon PowerShot G7 X Mark II was measured at 21 ISO settings from ISO 125 to ISO 12800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.
At base ISO (125) read noise is 3.41 DN, or 3.2 electrons at the sensor. From ISO 1250 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Full well at base ISO is about 13,284 electrons; unity gain is around ISO 120.
Canon PowerShot G7 X Mark II read noise table
| ISO | Read noise (DN) | log₂ |
|---|---|---|
| 125 | 3.411 | 1.77 |
| 160 | 3.891 | 1.96 |
| 200 | 4.595 | 2.20 |
| 250 | 5.315 | 2.41 |
| 320 | 6.409 | 2.68 |
| 400 | 7.568 | 2.92 |
| 500 | 9.000 | 3.17 |
| 640 | 11.004 | 3.46 |
| 800 | 13.177 | 3.72 |
| 1000 | 16.000 | 4.00 |
| 1250 | 18.896 | 4.24 |
| 1600 | 23.425 | 4.55 |
| 2000 | 28.443 | 4.83 |
| 2500 | 34.060 | 5.09 |
| 3200 | 43.713 | 5.45 |
| 4000 | 54.192 | 5.76 |
| 5000 | 67.182 | 6.07 |
| 6400 | 86.223 | 6.43 |
| 8000 | 107.635 | 6.75 |
| 10000 | 133.436 | 7.06 |
| 12800 | 168.897 | 7.40 |