I am currently looking for a lens to use on my D600 for wildlife and birding. I am currently using a 70-300mm VR (a hold over from my DX days). The three I am considering are the 300mm af-s f4, 70-200mm f4 and the 80-400mm. I currently have a tc-14eII. What I am looking for is high performance. Does the 80-400mm really give that to me on a 24mp camera? It is not compatible with the teleconverter. Does the 70-200 perform well with a 2x teleconverter? I have used the 300 with a converter and have been happy with the outcome. Now that I am ready to buy, which one do I go for? Thank you in advance for your input.
My experience with all three lenses is the AFS 300mm + the TC-14E is slightly sharper than the AF 80-400mm VR at 400mm. It also works nicely with the TC-17E on my D800. The AFS 70-200mm + TC-20EIII has the least resolution.
The AF 80-400mm lens is quite sharp with my D3X and D800. It will work with a 3rd party 1.4 extender like the Kenko Pro but the focus speed will be much too slow for birding. So of the three I would recommend the AFS 300mm f4 lens.
But I'm really anxious to see the new AFS 80-400mm lens. It should be better than the three setups above. I just have to sell a lot of stuff in order to afford it.