How difficult would it be for someone like a CV to develop a negative diopter converter as part of a LTM or M adapter that would restore the WA the sensor eliminates. A teleconverter in reverse. It would be "standardized" for certain focal lengths i.e. a 15-21mm or a 24-35mm and only 1 camera thus not trying to accomplish too much? I understand it would put more glass in the path - but at what price?