A long-reaching zoom characterized by its versatility, the EF 200-400mm f/4L IS USM Extender 1.4x from Canon is a medium to super-telephoto distinguished by its unique optical design and fast performance. Featuring a built-in 1.4x extender, you can quickly and intuitively switch between the native 200-400mm f/4 setting and an effective 280-560mm f/5.6 for greater reach. Benefitting this unique design is a sophisticated optical layout, which includes one fluorite element and four ultra-low dispersion elements to control chromatic aberrations and color fringing for increased clarity. A Super Spectra coating has also been applied to individual elements to reduce lens flare and ghosting for greater color accuracy and contrast when working in bright or backlit conditions.