I haven't tried with a TC yet, but I got a good deal on the 300 F4 which is why I bit - they aren't usually cheap, but I picked mine up from an avid lens collector who had every conceivable Minolta legend, and didn't need this one anymore...he lives nearby, so the price was fantastic, and I got to check it out in person before buying. ; All parts intact, including case, caps, wipes, hood, filters, etc...without so much as a scratch. ; This guy had 400 F4.5, 600mm F4, and 300mm F2.8...some seriously nice stuff!