<p>Thanks to David for the good question. I, too, 200-400\4vr and D300. 200-400 has a big problem with the accuracy of AF. Adjusting the number of AF depends on the distance and the focal length at the same time. I created a table with a focal length, the distance to the target and the setting of AF tune. Now my brain melted.<br />I am very much encouraged by the latest configuration АF tune D500. Friends, if I can finally adjust the autofocus, taking into account the distance to the object? I know that Sigma attempted. Can I hope that Nikon will allow me to set up 200-400 and I will not continue to shed tears?<br /> I apologize for my English.</p>