Canon 24-105/4 IS II Features. Canon L-series zoom covering a versatile wide-angle to short-telephoto range; Constant f/4 maximum aperture for consistent illumination; Redesigned optics with four aspherical elements for minimized distortion and spherical aberrations; Air Sphere Coating on individual elements to suppress flare and ghosting The Canon EF 24-105mm f/4L IS USM ($999.99) is a pricey lens in the company's premium line of L-series glass. Its design is appealing on paper: a 4.4x zoom with a maximum f/4 aperture The Canon RF 24-105mm F4L IS USM has relatively good sharpness, better than the EF Mark II version, but the lower resolution of the 30 MP sensor in the Canon EOS R should be taken into account in this comparison. Despite that, sharpness in the center is a little lower than expected when wide open at 24 mm, and there’s noticeable astigmatism qJPC74.