title: setting UIImageView content mode after applying a CIFIlter
body: <p>Thanks for looking.</p>
  
  <p>Here's my code</p>
  
  <pre><code> CIImage *result = _vignette.outputImage;
  self.mainImageView.image = nil;
  //self.mainImageView.contentMode = UIViewContentModeScaleAspectFit;
  self.mainImageView.image = [UIImage imageWithCIImage:result];
  self.mainImageView.contentMode = UIViewContentModeScaleAspectFit;
  </code></pre>
  
  <p>in here <code>_vignette</code> is correctly set up filter and image effect is applying to the image correctly. </p>
  
  <p>I'm using a source image with resolution 500x375. My imageView has almost iPhone screen's resolution. So to avoid stretching I'm using AspectFit.</p>
  
  <p>But after applying effect when I'm assigning the result image back to my imageView it streches. No matter which <code>UIViewContentMode</code> I use. It doesn't work. It seems it always applies <code>ScaleToFill</code> regardless the filter I've given.</p>
  
  <p>Any idea why is this happening? Any suggestion is highly appreciated.</p>