I would really like to find a Canon EF mount, with elec. i.e. auto, short ext. tube. Less than 12mm. Like 9 or 8mm. Anyone aware of such a thing? How about taking a Canon or Kenko 12mm tube (or longer) apart and doing some machnie work? I do own a set of manual ext. tubes. They say the shortest is 9mm but by the time you add on the necessary front and back plates, it is over 12mm.

