---
title: subjectMotion
framework: AVFoundation
role: symbol
role_heading: Type Property
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, tvOS 27.0+]
path: avfoundation/avcapturedeviceexposuresignal/subjectmotion
---

# subjectMotion

When enabled, auto exposure may close the aperture or decrease the exposure duration to reduce motion blur when there is a lot of motion in the scene.

## Declaration

```swift
static let subjectMotion: AVCaptureDeviceExposureSignal
```

## See Also

### Exposure signals

- [document](avfoundation/avcapturedeviceexposuresignal/document.md)
- [flicker](avfoundation/avcapturedeviceexposuresignal/flicker.md)
- [groupPhoto](avfoundation/avcapturedeviceexposuresignal/groupphoto.md)
- [starburst](avfoundation/avcapturedeviceexposuresignal/starburst.md)