Canon Extender EF 1.4x III Ideal for press, sports and nature photographers, this compact extender extends the focal length of Canon L-series telephoto or telephoto zoom lenses by a factor of 1.4 with optimized AF performance and communication between camera and Lens. More focal length The EF 1.4x III extender is designed specifically for Canon',s L-series IS super telephoto lenses. It extends their focal length by a factor of 1.4, and is designed to have virtually no impact on the Lens',s outstanding performance and image quality. First-class construction Optimized materials in the lens barrel for reflection reduction, as well as a coating on the outer edges of the lenses, reduce aperture reflections. The extender is excellently protected against dust and splash water - this also contributes to the high image quality. Optimized communication between lens and camera The integrated microprocessor ensures precise data transfer of the subject parameters between the Lens and the camera. This ensures precise automatic focusing. Suitable for many Canon telephoto and telephoto zoom lenses of the L series The Extender EF 1.4x III is suitable for most Canon telephoto and telephoto zoom lenses of the professional L series. It extends the focal length while reducing the effective aperture of the Lens by one stop.