Canon EF 200-400mm f/4L IS USM Extender 1.4x - Canon EF Mount

The Canon EF 200-400mm f/4L IS USM Extender 1.4x is a unique professional zoom featuring a built-in teleconverter that can be engaged via a mechanical lever. This allows the focal range to be instantly increased to 280-560mm at f/5.6. It is designed for maximum flexibility in wildlife and sports environments where changing lenses is impractical. The primary check for a used model is the engagement mechanism of the internal extender; it should click into place firmly without any play or error codes on the camera. SDS inspects the weather sealing around the extender switch and the smoothness of the zoom ring. Because of the complex internal optics, we verify that the lens maintains sharpness across the entire zoom range and with the extender engaged.