Key Features EF-Mount Lens/Full-Frame Format Aperture Range: f/4 to f/22 Four Aspherical Elements Air Sphere and Fluorine Coatings Ring-Type Ultrasonic Motor AF System Optical Image Stabilizer Weather-Sealed Construction Rounded 10-Blade Diaphragm Show Less An advanced one-lens solution, the EF 24-105mm f/4L IS II USM is a Canon L-series zoom covering wide-angle to short-telephoto focal lengths and featuring a constant f/4 maximum aperture. The version II of this popular lens sports a redeveloped optical design, which includes four aspherical elements to significantly reduce distortion and spherical aberrations