If you could only have one lens, many photographers would pick the upgraded EF 24-105mm f/4L IS II USM Lens from Canon due to its exceptionally versatile zoom range from wide-angle to short telephoto, a constant f/4 aperture, and an outstanding build quality befitting an L-series lens. This version II of the popular lens makes improvements to image quality through the use of a new optical design with four glass-molded aspherical elements, which helps to limit vignetting in your images. Also, it uses an Air Sphere Coating to reduce ghosting and flaring.
A ring-type Ultrasonic Motor AF system provides fast and accurate autofocus while built-in optical image stabilization can help compensate for about 4 stops of shutter speed, minimizing the effects of camera shake. This lens also offers a zoom lock switch to prevent lens creep when not actively in use as well as an internal focus system. Full-time manual focus override is available for making adjustments regardless of the AF mode. Additionally, it has a rounded 10-blade aperture diaphragm for smooth out of focus elements.
As with all L-series lenses, this optic has a dust- and water-resistant construction thanks to numerous seals that prevent intrusion when working in inclement weather. It also uses a fluorine coating on the exposed front and rear elements to help prevent smudges and to make cleaning easier.