Focus in the middle of the screen

Question

If I do this in Visual Studio in C #:

  camera = new Photo Camera (CameraType.Primary);
  cameraViewBrush.SetSource (camera);
               
  cameraView.Width = 1305;
  cameraView.Height = 980;
                
  camera.Focus ();

I only ever get to see in the picture the upper left corner.
How can I scroll through the image? move or portal?
Sincerely:
Uwe Reinermann