Sun 17-Feb-13 02:58 PM | edited Mon 18-Feb-13 02:35 AM by torwood
Sometimes Ken Rockwell is a bit too glib and biased with his review comments. The only limitations to the 80-400VR are:
1) It is an older AF screw-drive lens (not a modern motor-in-lens AFS) moving a lot of glass elements. As such, it is slow focusing at all focal lengths for photographing things that move. That said, the better (more robust AF motor) the camera body, the faster focusing the lens will be. It will focus much faster on a D4 than on a D3200. This is related to pro vs amateur bodies more than FX vs DX, though the FX bodies are typically the pro bodies (D600 excepted).
2. The lens is less sharp in the corners than a 400mm prime at 400mm, especially on FX, which exposes the corners more. Duh!!! It also costs $1,600, and not $9,600. The lens is reputed to be sharp enough at 400mm stopped down a little, and it's a hell of a lot sharper than the 400mm lens you don't have because you can't afford the 400mm prime. From reading this site, I think the jury is still out as to whether the 80-400VR is sharper, less sharp, or the same as the 300mm f4 + 1.4TC. The latter is AFS and the same price, but it's also still f5.6, and potentially limited by not being able to zoom. The 300 f2.8 + 1.4TC is faster and probably sharper, but it's also over $5,000.
3. The lens may be upgraded soon (at least we've been hoping for this for years).
4. As an older design with slow AF, I think the lens is over-priced, both new and used. I just don't think it is a good value. But, that is just my personal opinion.
These are the "limitations", and they really have very little to do with DX vs FX.
Correction: The 80-400 won't even AF on a D3200. You need at least a D90 or D7000 to AF this lens. Sorry about that.