yeah i was thinking it should work too since thats pretty much all an extension tube is. Plus, the inside of it is all matte black and slightly ridged so it works as baffling so theres not too much light bouncing around , the teleconverter only cost me 40 dollars at a camera swap meet, so i didnt feel too bad about taking it apart. It still worked fine and everything, but i never really used it because it didnt seem to give me very good results on anything but my 50mm lens anyway. All the pieces are stacked in order and taped together in a case now so if i ever decide to put it back together i can, but honestly i dont really see that happening anyway... i'll post a couple other examples in a bit if anyone wanted to see them