---
title: exposureDuration
framework: avfoundation
role: symbol
role_heading: Instance Property
path: avfoundation/avcapturedevice/exposureduration
---

# exposureDuration

The length of time over which exposure takes place.

## Declaration

```swift
var exposureDuration: CMTime { get }
```

## Discussion

Discussion The exposure duration is between the active format’s minExposureDuration and maxExposureDuration. To set the exposure duration, call the setExposureModeCustom(duration:iso:completionHandler:) method. This property is key-value observable.

## See Also

### Configuring exposure manually

- [setExposureModeCustom(duration:iso:completionHandler:)](avfoundation/avcapturedevice/setexposuremodecustom(duration:iso:completionhandler:).md)
- [iso](avfoundation/avcapturedevice/iso.md)
- [lensAperture](avfoundation/avcapturedevice/lensaperture.md)
- [activeMaxExposureDuration](avfoundation/avcapturedevice/activemaxexposureduration.md)