This versatile, constant aperture lens incorporates a newly designed Silent Drive module for faster, smoother and quieter AF. It is constructed with 15 elements, including 3 aspherical and 3 glass low-dispersion elements, in 13 groups, delivering significantly reduced chromatic and spherical aberrations. A large front element means minimal vignetting and low distortion, while a One-Touch Focus Clutch Mechanism makes switching from AF to manual focus easy: all the user need do is to snap the focus ring back toward the camera to engage manual. Minimum focusing distance is 0.28 meters, allowing for highly creative depth of field either wide open or closed down to its minimum f/22 aperture.