title: Manual focus stacking Camera2 Api
body: <p>I am trying to implement an android app with the <code>Camera2</code> api, which should take pictures with various focus distances, something like focus stacking.</p>
  
  <p>I have trouble with the manual focus, how do I trigger the focus action?
  The <code>LENS_STATUS</code> is always static, so my images are always unfocused - no focusing has been done.
  I have set the <code>AF_MODE</code> to <code>OFF</code> and setting the focus distance with:</p>
  
  <pre><code>captureBuilder.set(CaptureRequest.LENS_FOCUS_DISTANCE, minFocus);
  </code></pre>
  
  <p>Can anyone give a hint on how to trigger camera to focus?</p>