Sigma 28-200mm f/3.5-5.6 Aspherical (IF) is compact, lightweight internal focusing zoom lens. The wide to telephoto focal lengths are the most frequently used focal range. The triple-cam internal focusing technology prevents the filter threads from moving during focusing. Its lens optical construction consist of 16 elements in 14 groups with one aspherical glass elements for high contrast and edge-to-edge sharpness while correcting chromatic, spherical and coma aberrations. Zoom lock mechanism is incorporated to prevent creeping due to its own weight. Ideal for travel and snapshot photography, the 28-200mm is a versatile and reliable lens allowing you to produce stunning photos.