1. New-generation, high-performance Star-series lens to deliver ideal image quality Anticipating the further advancement of SLR camera bodies in the future, PENTAX has designed this lens to deliver extra-clear, high-contrast images with edge-to-edge sharpness by compensating various aberrations to a minimum, while greatly enhancing resolving power — two factors absolutely essential in the next-generation Star series. It provides exceptionally high imaging performance even at open aperture, a beautiful bokeh (defocus) effect and outstanding image rendition at close ranges — all reasons why it produces high-quality, well-defined images. It also boasts an extra-large F1.4 maximum aperture, useful with many different subjects in a range of applications, including portraiture with an effectively defocused background, handheld shooting of indoor scenes and scenic photography. It helps the camera to produce a bright, clear viewfinder image that will inspire the photographer's creativity and imagination. 2. State-of-the-art optical technology This lens incorporates three Super ED (Extra-low Dispersion) glass optical elements to effectively minimize chromatic aberration, and a glass-molded aspherical optical element to effectively compensate for spherical and comatic aberrations and field curvature to deliver extra-clear, high-contrast images with edge-to-edge sharpness, even at open aperture. It also reduces distortion to nearly zero at a focusing distance of four meters to deliver well-defined, distortion-free images over the entire focusing range, from the minimum focusing distance to infinity. This lens is also treated with high-grade, multi-layer HD Coating, which reduces average reflectance in the visible ray spectrum to less than 50% of conventional multi-layer coatings, effectively reducing flare and ghost images to a minimum even in demanding lighting conditions such as backlighting. HD is the abbreviation of High Definition. 3. Newly designed, large ring-type SDM In order to deliver the highest image quality possible over the entire focusing range — from the minimum focusing distance to infinity — this lens features an newly designed, large ring-type SDM to efficiently drive the focusing mechanism, which consists of a larger number of optical elements than ordinary lenses, and is required to shift heavy rear-optical-element groups in unison. Generating a torque approximately 1.3 times that of the unit installed in the HD PENTAX-D FA50mm f1.4 SDM AW, this new SDM assures flawless, high-speed autofocus operation. 4. Dustproof, weather-resistant construction Developed as an AW (All Weather) model, this lens features a dependable dustproof, weather-resistant construction with eight special seals to prevent the intrusion of water into the lens barrel. When paired with a dustproof, weather-resistant PENTAX digital SLR camera body, it assures a durable, reliable digital imaging system that performs superbly in demanding shooting settings — even in rain or mist, or at locations prone to water splashes or spray. 5. Other features ・Nine-blade, round-shaped diaphragm to produce a natural, beautiful bokeh (defocus) effect up to the F2.8 aperture setting, while minimizing the streaking effect of point light sources ・Exterior design that facilitates focus-ring operation in manual-focus shooting and provides a firm hold ・Electromagnetic diaphragm-control mechanism for flawless, high-precision exposure control during video recording ・SP (Super Protect) coating to keep the front surface free of dust and spots This mechanism is available when the lens is mounted on a K-1 Mark II, K-1, K-3 II, K-3, KP, K-70, K-50, K-S2 or K-S1 camera body. "