I have a Canon 70-200 2.8L II which I use with 1.4x and 2x MkII Canon TCs. If I change the TCs for a 2x MkIII will the image quality from it in the focal lengths covered by the 1.4 MkII be as good as the 1.4? Of course I appreciate that I will go from f4 to f5.6 in the focal lengths that overlap. Thanks in advance for any and all advice.