There are several generations, the newest are the E-II and the latest E-III series, which includes an
aspherical lens.
Teleconverters need a
fast lens for fast, reliable
autofocus. Depending on brightness, contrast and needed autofocus-speed, one should have a minimum total
aperture between 11 and 5.6. A total aperture of 8 corresponds to a lens aperture of 5.6, 4 and 2.8 with a 1.4×, 2× and 3× teleconverter, respectively. Sometimes teleconverters do not convert aperture and
focal length data included in the
Exif information, even if the actual focus and exposure still will be correct. Not every teleconverter will support autofocus with every lens. Teleconverters are often recommended only for lenses with minimum telephoto focal length or equivalent zoom range. All AF-I and AF-S teleconverters support lenses with
optical image stabilization (Nikon VR). ==Models==