Originally Posted by
Manfred M
Ted / Dan - both my explanation and Canon's explanation in the article you posted are simplifications of what is really happening. Both are correct to a certain extent, but real life is a lot more complex ...
Ted - your response is similar to what I got from the controls systems engineers when we tried to integrate the control system in a real world operating equipment and the devices did not operate as required and sometimes not at all. Sometimes it was a mechanical design issue (my problem), sometimes it as a control system issue (the control engineer's problem) and sometimes it was a component issue (operating in spec, but at the limits of the spec; that tended to be an issue both of us were involved in resolving, but it generally was easier and less expensive to change the control system than the mechanical element).