Hi, It seems that the best TC to match the lens is the TC-1.4, this will be shown in the nikon lens hand paper instructions. An alternative to the addition of the TC1.4 is to use the lens in DX mode which will give a maximum of 600mm, but this would be at 10.xx mp.
All you're doing in DX mode is cropping the photo in camera instead of in software. It doesn't give you a 600mm lens. What it gives you is the angle of view of a 600mm lens with the 1.4x TC attached. I don't see the benefit of using DX mode on the D600 unless you have an aversion to manually cropping. The reason photographers like DX cameras for things like wildlife is you get a larger image from a hi resolution DX camera because you're putting more pixels in a smaller area which allows for more enlargement. You're quite right about the 10.x mp in DX mode but viewing the FX or the DX image will give you the same size image of the main object in the photo.
It could happen, but even if it did, what's to lose? The TC-14eII is already pretty darn good. There isn't a lot that can be done to improve it. You might also consider looking for a TC-14e (ie not II). It's optically and mechanically the same, but cosmetically different. For some reason they go for less money on the used market than the TC-14eII. And there's not a whole lot that can go wrong in a TC, either...
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!
Any of the Nikon tele-converters will fit the lens. However, the only one that is likely to give reasonable image quality and functional AF is the TC-1.4E II.
AF will likely only work reliably on cameras that have f8 capable sensors in their AF systems. These include the D7100 (centre sensor only) , the D800 (11 of 51 sensors)and the D4. I don't know about the D600/D610 but I think they also have some f8 capable sensors.
With the 1.7x and 2.0x converters the combination will be reduced to f9.5 and f11 respectively which is insufficient for reliable AF. You could use these TCs but would likely have to focus manually. Due to the small apertures, the viewfinder image is appreciably dimmed and so even manual focus can be quite difficult in this situation.
TCs also degrade image quality with the degradation somewhat proportional to the magnification. A lens that is just acceptably sharp with the 1.4TC will likely not be satisfactory with the 1.7 and 2.0 but this varies from lens to lens.
People using the 80-400G AF-S lens with the 1.4 TC have reported reduced function in the AF. I have seen reports of hunting, chattering (hesitant to lock on a subject) and slow AF. It is possible the reviewer's subjects were not ideal and that the performance may actually be acceptable in decent light with a contrasted subject. I have not used one with the converter fitted.
As always in this situation, it helps to always try to use only the f8 capable sensors and focus on contrasted portions of your subject such as an edges having different colour or brightness on the two sides of the edge.