Today was the first time I tried using my D600 with a TC. My D600 only auto focuses intermittently with the TC 1.4 attached. No problem with other lenses. Have any of you had a similar problem? Any idea what might be the problem? Thanks for any help you can offer.
Which 1.4 TC and what lens were you using it with? When you say it works fine with other lenses what exactly are you referring to? Which lenses and with or without the TC. Is this the Nikon 1.4 EII TC?
The situation you describe could be related to lighting levels or sensor choice. AF does not work all the time on any camera - and adding a teleconverter increases the odds of a miss. The layout of regular and cross sensors is different with each camera model. In the future if you have such a problem, try using just the center sensor. If that does not work, try using an easier AF target that is near your subject but with higher contrast.
All of my cameras refuse to AF occasionally. If the above suggestions do not work, sometimes you can manually focus to get close and then AF kicks in properly.
The replacement worked fine with the TC, but there was a thin line through the center of each image I took. Soooo sent it back again. Third time was charm it seems to work well. I am talking about Nikon refurbished units!