Not relevant because (a) Canon don't make a 1.7x teleconverter, and (b) Canon cameras have a firmware setting which disables autofocus when the lens doesn't have a large enough aperture, but Nikons don't.My 70-200 F/4 will focus on my Nikon D700 with a TC17. Even in this low winter gloom.
i stand double corrected ,thank you for clarifying it properly .hopefully now the bitching will stop and the poor O/P will get the answer he requires .
I must remember that next time I fit my 1.4 or 2x converter (Canon) to my 70/200 F4 IS L, especially when I compare the results to my 400 5.6L (no IS), despite being "not recommended" (by whom) they seem to work rather well, they certainly represent good value for money in terms of AF and IQ. Maybe I'm just lucky, either that or the 5Dmk3 reacts better than some other cameras or manufacturers.