Bright f/1.4 maximum aperture suits working in low-light conditions and also affords greater control over the depth of field. Integrated manual aperture ring for tactile exposure control; this ring also features an 'A' position for automated, camera-based aperture selection
The SMT stepping motor enables quick, quiet, and precise autofocus performance along with a full-time manual focus override. Additionally, an internal focusing design maintains the overall lens length during use for improved handling and quicker response
To adjust the aperture automatically, turn the aperture knob at the bottom of the lens to A, which means the camera controls the aperture; To adjust manually, turn the aperture ring at the bottom of the lens directly by hand
The lens adopts HD Nano Multilayer Coating & STM Step Motor, 11 elements in 10 groups, 9 aperture blades, including 2 ED lenses and 2 high refraction index lens