The biggest change to the optical design of the lens is the introduction of a floating focusing element, enabling the lens’ high-resolution .5x “half-macro” magnification, shrinking the minimum focusing distance to 3.5″ at 70mm. This increased resolution is available across the entirety of the zoom range, as is the lens’ improved corner-to-corner sharpness. The lens features aspherical, Advanced Aspherical, extra-low dispersion, and extra-low dispersion aspherical elements to reduce and suppress chromatic and spherical aberrations. Nano AR Coating II controls flare and ghosting, while the rounded, nine-blade diaphragm supplies the lens with its signature deep, soft, G Master bokeh.