A similar question was raised last year (http://wetpixel.com/...l=teleconverter) but did not get answers. I hope you fare better as my reply won't count as an answer. I just checked out the tread to find out why anyone would want to do this in the first place. It is much easier to make a 24mm lens than a 15mm lens, so why would you add the extra size, weight, glass, and expense of a TC, which also reduces light captured by the sensor, to fake a 24mm and not use the real thing? I also seem to recall that canon teleconverters came with the message that they were designed for use with long focal length lenses and not recommended for wide angle lenses, although that may not be a real concern.