The radius of the shutter. The value is a percentage of the image size. Default value is 0.25.
This effect uses the Center, Radius and AspectRatio properties to construct the shutter area. The area outside the shutter are cleared using the color set in the ClearColor property.
For XAML example, refer to CircularShutterEffect.
For C#/VB examples, refer to CircularShutterEffect.