Dedicated 1.4x APO Teleconverter features a high performance 5 element/3 group optical design, and it is optimized for use with long telephoto and tel

Dedicated 1.4x APO Teleconverter features a high performance 5 element/3 group optical design, and it is optimized for use with long telephoto and telezoom lenses. The high performance optical characteristics of these teleconverters maintain the optical performance of the compatible lenses with which they can be used.