Pentax 600mm f/4 ED IF SMC P-FA

(From Pentax lens literature) The Pentax SMC P-FA 600mm f/4 ED IF telephoto is an ideal lens for professionals and advanced amateurs interested in sport and wildlife photography. It incorporates high-refraction extra low dispersion (ED) glass elements to produce a high-resolution, high-contrast image and an internal focus system to make focusing smoother and faster. Like all Pentax lenses, it features our acclaimed SMC multi-layer coating to lower surface reflection, reduce ultraviolet rays, and deliver clear, high-contrast images.