title: How can the auto-focus of camera be explained using pinhole camera model?
body: <p>Shifting the auto-focus in real-world camera doesn't change the focal length, rotation, or any other camera parameter in pinhole camera model. However, it does shift the image plane and affect the depth of field. How is this possible?</p>
  
  <p>I understand that complex mechanism of real-world camera cannot be easily explained with pinhole camera model. However, I believe that there should be some link between them as we use this simplified model in various real-world computer vision applications.</p>