title: How to properly instantiate CIDetector class object in iOS 5 face detection API
body: <p>reading the Apple's documentation i tried using it's new face detection API but with no luck,, although there are no compile or runtime errors the instance method <strong><em>featuresInImage</em></strong> always return an array of CIFeature objects with null values.</p>
  
  <p>First timer on stackoverflow, still tried my best to be short and specific.</p>