title: Setting the cameras focus in ios7 xcode. opencv
body: <p>I am making an ios 7 app that will calibrate my iphones intrinsics and then reconstruct 3d points using 2 iphones. For this I need to lock the focus while running the opencv checkerboard calibration. Then when I go to use this intrinsic calibration for reconstructing and the detection of objects, I need to set and lock the phones focus back to the same value that was used when running the intrinsic calibration.</p>
  
  <p>So how can I set the focus of my iphones camera to a given value? I have done some googling but have uncovered nothing.</p>
  
  <p>Cheers.</p>