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# iso

The current exposure ISO value.

```
var iso: Float { get }
```

## Discussion

This property controls the sensor’s sensitivity to light by applying a gain value to the signal. This value is between the active format’s [`minISO`](/documentation/AVFoundation/AVCaptureDevice/Format/minISO) and [`maxISO`](/documentation/AVFoundation/AVCaptureDevice/Format/maxISO) values. Higher values result in noisier images.

To set the ISO, call the [`setExposureModeCustom(duration:iso:completionHandler:)`](/documentation/AVFoundation/AVCaptureDevice/setExposureModeCustom(duration:iso:completionHandler:)) method.

This property is key-value observable.

---

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