Sigma 18-200mm OS lens : The Sigma Corporation is please to announce the new 18-200mm F3.5-6.3 DC OS lens. This high zoom ratio lens is exclusively designed for digital SLR cameras and is capable of covering a wide range of focal lengths from wide angle to telephoto. It is equipped with Sigma’s own unique technology OS (Optical Stabilizer) function. This function uses two sensors inside the lens to detect vertical and horizontal movement of the camera and works by moving an optical image stabilizing lens group, to effectively compensate for camera shake. It automatically detects movement of the camera and compensates for camera shake when shooting moving subject such as motor sports.