title: How can I detect if an iOS device supports the blur effect?
body: <p>It appears that different iOS devices render <code>UINavigationBar</code>s with <code>barStyle = UIBarStyleBlack</code> and <code>translucent = YES</code> very differently. Consider:</p>
  
  <p>iPhone 4, no tint:
  <img src="https://i.stack.imgur.com/uDhzP.png" alt="iPhone 4, no tint"></p>
  
  <p>iPhone 5, no tint:
  <img src="https://i.stack.imgur.com/M71iA.png" alt="iPhone 5, no tint"></p>
  
  <p>iPhone 4, <code>barTintColor = [UIColor colorWithWhite:0.0f alpha:0.5f]</code>:
  <img src="https://i.stack.imgur.com/tMuOv.png" alt="iPhone 4, tinted"></p>
  
  <p>iPhone 5, <code>barTintColor = [UIColor colorWithWhite:0.0f alpha:0.5f]</code>:
  <img src="https://i.stack.imgur.com/CPsLK.png" alt="iPhone 5, tinted"></p>
  
  <p>The iPhone 5 produces the desired effect without a tint, but the 4 is opaque. Adding a semitransparent tint makes the 4 look good, but screws up the 5.</p>
  
  <p>The same holds true for the iPad 2 and 3, and theoretically any device that does not support the iOS 7 blur effects.</p>
  
  <p>Short of blacklisting these older devices, how can I detect if a device supports the blurring so that I can conditionally work around the rendering differences? Or is there a way to normalize the appearance without using a tint at all?</p>