Constant f/4 maximum aperture maintains consistent illumination throughout the zoom range.

Three aspherical elements and one ultra-high refractive index element help to minimize distortions and spherical aberrations throughout the zoom range in order to maintain edge-to-edge sharpness and illumination.

One extra-low dispersion element greatly reduces chromatic aberrations and color fringing in order to produce a high degree of clarity and color accuracy.

The autofocus focus system employs both a double-magnet linear motor to deliver impressively fast and precise focusing performance while remaining compact. A focus clutch mechanism has also been incorporated, which allows for near-instant AF/MF switching.

Splash, dust, and freezeproof design benefits working in inclement weather conditions down to -14°F.

Rounded nine-blade diaphragm contributes to a pleasing bokeh quality.