A lens extender is an adapter lens that fits between the camera body and the lens and extends the focal length of the lens. While maintaining the lens’s high optical performance, the Extender EF1.4X II increases the focal length by 1.4 times and Extender EF2X II doubles the focal length.

Both Canon extenders feature the same exceptional levels of water- and dust-resistance as are found in the company’s flagship professional-model EOS-1V AF SLR camera, and IS-type super-telephoto lenses, which are equipped with an Image Stabilizer to correct for the effects of camera shake. The revamped optical systems employed in the new extenders realize even higher image quality than the previous Canon Extender EF1.4X and Extender EF2X models, launched in November 1988 and October 1987, respectively. Furthermore, the new extenders offer compatibility with the same EF telephoto lenses as the previous extenders^*.

* As of February 14, 2001.