Summary: The TC-20E-II is the 4th generation of AF-S/I teleconveters from Nikon, All the TC20's are opically excellent however they are speclialized teleconverters designed for Nikon's professional telephoto and telephoto zoom lenses.
Summary: I have the Nikon 500mm f4,with the TC-14EII tele converter attach on it,I have another 200mm extra on reach,the focus and speed works extremely well with it,I am using it most of the time on bird shoots,a must if you like to photography wildlife.
Best Teleconverter for the least image degradation
10 December 2010
Summary: I had a TC1.7 and was unhappy with some of the images taken. Returned to the 1.4 and I am pleased with the results. When I upgrade to my next lens, I will probably sell the TC as I will not need the reach
Good product, but do your homework before ordering
Tom Coyner, Onsite Studios, Amazon
14 December 2009
Summary: Buying any teleconverter takes a good bit of homework. Teleconverters are not nearly as compatible with lenses - including of the same manufacturer - as most people may assume. Though I use this with an older Nikkor 70~200mm lens for sports events, it is actually designed for longer telephotos.