KEY FEATURES:- The worlds first teleconverter to utilize an aspherical lens element A new optical design that offers superior contrast and resolution An FX-format compatible teleconverter that extends the focal length of the primary lens by 2 Utilization of an aspherical lens element enabled a more compact and lightweight teleconverter teleconverter that extends the focal length of the primary lens by 2 Utilization of an aspherical lens element enabled a more compact and lightweight teleconverter Using this teleconverter with a lens decreases the effective aperture by two stops
