title: canSetSessionPreset:AVCaptureSessionPreset1920x1080 returns 'yes' on iPhone 4
body: <p>I want to check if the iPhone the user has supports full HD video capturing. I found out, that I should ask the AV session, if</p>
  
  <pre><code>avSession = [[AVCaptureSession alloc] init];
      [avSession beginConfiguration];
      if ([avSession canSetSessionPreset:AVCaptureSessionPreset1920x1080]) {
          avSession.sessionPreset = AVCaptureSessionPreset1920x1080;
          NSLog(@"FULLHD");
      } else {
          avSession.sessionPreset = AVCaptureSessionPreset1280x720;
          NSLog(@"HDREADY");
      }
      [avSession commitConfiguration];
  </code></pre>
  
  <p>This works fine on iPhone 5 (which indeed supports full HD capturing), but on iPhone 4 tries too to set the preset, but clearly fails. What am I doing wrong?</p>
  
  <p>Thanks in advance,
  Matthias</p>