title: iOS AVFoundation different presets for still image and preview
body: <p>Is there a way to show preview (for example from modified frames) with a medium/low preset, and capture a still image with high/photo preset? Changing the preset doesn't work because it either fails or the camera fails to turn on in time..</p>
  
  <p>I've seen a similar question here, seems as if it was already solved but I don't see how that would show a low quality preview and capture a high quality still image:</p>
  
  <p><a href="https://stackoverflow.com/questions/12055350/switching-avcapturesession-preset-when-capturing-a-photo">Switching AVCaptureSession preset when capturing a photo</a></p>