my experences with TCs are that they work pretty well when the subject is closer to the camera like the shot Dave took above, but the main reason I use Tcs is that when I can't get close enough to the subject.usually the results are not quite good when the subject is farther, softer and CA are the main prblem. I prefer to just move my legs to get closer instead of use TCs or zoom lens. but my 1.4TC II with 300mm2.8 and 500mm 4.0 are pretty good.