A compact, lightweight standard zoom lens with superior optical performance plus a built-in Image Stabilizer. The IS system reduces the possibility of blurred photographs caused by camera shake, enabling hand-held photography in comparatively dim light without a flash or tripod. The IS system is composed of a pair of gyro sensors to detect vertical and horizontal motion and a microprocessor that compensates for it by shifting special IS lens elements in parallel with the perceived movement. At the wide-angle end of the zoom range, the equivalent shutter speed gain is approximately 1.5 stops while at the telephoto end, it is approximately 2 stops. In addition, the lens has a USM drive mechanism for optimum AF performance, and the pulse control diaphragm (EMD) ensures precise aperture control.