This telephoto zoom lens provides a large F4 aperture at all focal lengths. The new multi layer lens coating and lens design reduce flare and ghosting, a common problem with digital cameras, and also creates an optimum color balance through the entire zoom range. Two Special Low Dispersion (SLD) glass elements in the front lens group and another two in the rear group offer excellent correction of chromatic aberration. High optical performance is demonstrated throughout the entire zoom range. The internal focusing and zooming mechanism do not change the lens" overall length, assuring ease of handling and operation. A rotating tripod mount can be conveniently detached if required. Since the front of the lens does not rotate, a circular polarizing filter and Petal-type hood can be easily attached. High-speed focusing is possible when this lens is used with dedicated APO 1.4x EX tele-converter. With the optional APO 1.4x EX tele-converter, this lens becomes a 140mm to 420mm F5.6 AF zoom. With the APO 2.0x EX tele-converter, a manual focus zoom lens from 200mm to 600mm F8 is achieved.