In OpenCV 2.4.9, I'm using the Python camera calibration script (samples/python2/calibrate.py) to calibrate my camera. I've noticed though that the optional "square_size" parameter has no effect on the results. Am I just doing something wrong so that I'm getting no changes based on the square_size setting? Or is it just not used in this script. If so, why is it even an option? Thanks.