http://www.directorysky.com/entertainment/cheap-canon-ef-500mm-f4l-is-usm-super-telephoto-lens/ Canon EF 500mm f 4L IS USM Super Telephoto Lens for Canon SLR Cameras Features 1. f/4 maximum aperture 2. 500mm focal length 3. Fluorite and Ultra-low Dispersion-glass. image stabilizer. internal focusing. full-time manual focus 4. EF mount. super telephoto lens Mon, 30 Aug 2010 19:41:39 ICT en