From the Manufacturer An ultra-telephoto zoom lens, which overcomes image blur caused by camera shake.
Sigma APO 80-400mm F4.5-5.6 EX OS is one of several new products introduced at Photokina 2002 by Sigma Corporation of Japan (2-3-15, Iwado-Minami, Komae-shi, Tokyo, Japan).
Sigma's advanced Optical Stabilizer (OS) allows you to take great pictures with a long lens, even in low-light conditions. The image on the left was taken without Sigma's OS; the image on the right was taken with Sigma's OS. Sigma's OS (Optical Stabilizer) system detects camera shake by utilizing two sensors, and then by the movement of an optical stabilizing lens group. It is equipped with two optical stabilizer modes to compensate for image blurring.
Mode 1, determines the camera shake in vertical and horizontal panning and compensates blurring, this mode is effective when shooting static subjects.
Mode 2, detects the vertical camera shake, and overcomes blurring. It is especially effective with moving subjects such as motor sports etc.
Two Special Low Dispersion (SLD) glass elements in the front lens group and one in the rear group offer effective control of color aberration. This lens features full-time manual focusing and a removable tripod collar. The rear focus system prevents the front of the lens from rotating; a circular polarizing filter can be easily attached and used. This lens is also equipped with Zoom Lock Switch that eliminates "Zoom Creep". When this lens is used with the 1.4x EX or 2x EX Apo Tele Converters (optional), it becomes a 112-560mm F6.3-7.8 MF telephoto lens or a 160-800mm F9-11 MF ultra-telephoto lens respectively. The lens materials used in this new lens are lead and arsenic free ecological glass.