The EF 28-135mm f/3.5-5.6 IS USM Lens from Canon is a compact and lightweight zoom lens that offers superior optical performance plus a built-in Image Stabilizer. The IS system reduces blurred photographs caused by camera shake and allows for handheld photography in comparatively dim light without a flash or tripod. 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 an Ultrasonic Autofocus Motor (USM) for faster and quieter AF operation, and the pulse control diaphragm (EMD) ensures precise aperture control. manual focus override is supported for precise manual control even in AF mode. The minimum focus distance throughout the zoom range is 20".
The Optical Image Stabilization (IS) system is composed of a pair of gyro sensors to detect vertical and horizontal motion and a microprocessor that compensates for this motion by shifting special lens elements in parallel with the perceived movement. The IS system reduces blur in images shot in dim light and at long focal lengths.
The internal focusing mechanism allows the front of the lens to remain stationary and to easily accommodate specialty filters, such as polarizing filters.
An Ultrasonic Autofocus Motor (USM) provides fast, smooth and quiet autofocus action which is particularly important when shooting video with this lens.