---
title: fallbackPrimaryConstituentDevices
framework: avfoundation
role: symbol
role_heading: Instance Property
path: avfoundation/avcapturedevice/fallbackprimaryconstituentdevices
---

# fallbackPrimaryConstituentDevices

The fallback devices to use when a constituent device with a longer focal length becomes limited by its light sensitivity or minimum focus distance.

## Declaration

```swift
var fallbackPrimaryConstituentDevices: [AVCaptureDevice] { get set }
```

## Discussion

Discussion By default, this value contains the array of devices that the supportedFallbackPrimaryConstituentDevices property provides. The system throws an exception if you attempt to specify a device other than the ones found in the device array. This property is key-value observable.

## See Also

### Restricting camera switching

- [setPrimaryConstituentDeviceSwitchingBehavior(_:restrictedSwitchingBehaviorConditions:)](avfoundation/avcapturedevice/setprimaryconstituentdeviceswitchingbehavior(_:restrictedswitchingbehaviorconditions:).md)
- [primaryConstituentDeviceSwitchingBehavior](avfoundation/avcapturedevice/primaryconstituentdeviceswitchingbehavior-swift.property.md)
- [primaryConstituentDeviceRestrictedSwitchingBehaviorConditions](avfoundation/avcapturedevice/primaryconstituentdevicerestrictedswitchingbehaviorconditions-swift.property.md)
- [activePrimaryConstituentDeviceSwitchingBehavior](avfoundation/avcapturedevice/activeprimaryconstituentdeviceswitchingbehavior.md)
- [activePrimaryConstituentDeviceRestrictedSwitchingBehaviorConditions](avfoundation/avcapturedevice/activeprimaryconstituentdevicerestrictedswitchingbehaviorconditions.md)
- [activePrimaryConstituent](avfoundation/avcapturedevice/activeprimaryconstituent.md)
- [AVCaptureDevice.PrimaryConstituentDeviceSwitchingBehavior](avfoundation/avcapturedevice/primaryconstituentdeviceswitchingbehavior-swift.enum.md)
- [AVCaptureDevice.PrimaryConstituentDeviceRestrictedSwitchingBehaviorConditions](avfoundation/avcapturedevice/primaryconstituentdevicerestrictedswitchingbehaviorconditions-swift.struct.md)
- [supportedFallbackPrimaryConstituentDevices](avfoundation/avcapturedevice/supportedfallbackprimaryconstituentdevices.md)