---
title: subjectAreaDidChangeNotification
framework: avfoundation
role: symbol
role_heading: Type Property
path: avfoundation/avcapturedevice/subjectareadidchangenotification
---

# subjectAreaDidChangeNotification

A notification the system posts when a capture device detects a substantial change to the video subject area.

## Declaration

```swift
class let subjectAreaDidChangeNotification: NSNotification.Name
```

## Discussion

Discussion The system posts this notification only if the device’s isSubjectAreaChangeMonitoringEnabled property value is true.

## See Also

### Configuring camera hardware

- [lockForConfiguration()](avfoundation/avcapturedevice/lockforconfiguration().md)
- [unlockForConfiguration()](avfoundation/avcapturedevice/unlockforconfiguration().md)
- [isSubjectAreaChangeMonitoringEnabled](avfoundation/avcapturedevice/issubjectareachangemonitoringenabled.md)
- [Formats](avfoundation/capture-device-formats.md)
- [Focus](avfoundation/capture-device-focus.md)
- [Exposure](avfoundation/capture-device-exposure.md)
- [White balance](avfoundation/capture-device-white-balance.md)
- [Lighting](avfoundation/capture-device-lighting.md)
- [Color](avfoundation/capture-device-color.md)
- [Zoom](avfoundation/capture-device-zoom.md)