title: Blur effect does not fill the entire View
body: <p>I have a View controller that features a full screen UIImageView. When the controller loads, I just set a blur effect over the whole screen. The content mode for the UIImageView is set to scaleAspectFill. I set the blur effect like this:</p>
  
  <pre><code>@IBOutlet weak var previewImage: UIImageView!
  
  override func viewDidLoad() {
      super.viewDidLoad()
  previewImage.image = userPhoto     
  let blur = UIVisualEffectView(effect: UIBlurEffect(style: .Light))
  blur.frame = self.view.bounds
  previewImage.addSubview(blur)
  }
  </code></pre>
  
  <p>when I test the app on an iPhone 6 I get this result: </p>
  
  <p><a href="https://i.stack.imgur.com/ZAJdx.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZAJdx.jpg" alt="Iphone Screen Capture"></a></p>
  
  <p>There's an offset on the right an I can't figure out why. The picture underneath if is properly full screened but I can get the blur effect to fit over it...</p>
  
  <p>****EDITED**** </p>
  
  <p>I applied the blur effect to the VC's view directly and now it works just fine, but I'd like to know why it doesn't work when I add the subview to the UIImage View...</p>