PENTAX conducted an extensive review of the in-house standards for the top-of-the-line Star series, to further improve the imaging performance of PENTAX digital SLR cameras — both existing and future models. This review will result in the development of the new generation of Star-series lenses. The first model of this series is the HD PENTAX-D FA★ 50mmF1.4 SDM AW. This single-focus standard lens with a 50mm focal length — something familiar to nearly every photographer — delivers the highest image quality possible in AF-compatible, single-focus standard lenses, symbolizing the remarkable imaging power of the new-generation Star series. It has been designed to optimize the performance of the image sensor installed in the PENTAX K series of 35mm full-frame digital SLR cameras by greatly improving resolving power. It also delivers exceptional resolution and color reproduction even at open aperture, enhancing the image quality assured by the camera’s Pixel Shift Resolution System. The HD PENTAX-D FA★ 50mmF1.4 SDM AW is a large-aperture, single-focus standard lens with a maximum aperture of F1.4, which ensures the highest image quality of all lenses designed for use with K-mount digital SLR cameras.
In addition to a modified gauss-type rear focus-lens group, the lens also features a group of aberration-correction elements in its front optical group, which effectively compensate for aberrations which cannot be corrected by a modified gauss-type group. The lens therefore assures uniform resolving power and excellent color reproduction from the center to the edges of the image field. Its minimum focusing distance has been reduced to a mere 40 centimeters. By incorporating a powerful, high-torque ring-type ultrasonic wave motor SDM, it also shifts the heavy rear optical group more efficiently and smoothly, for responsive, high-speed autofocus operation.
The lens is treated with PENTAX-developed Aero Bright Coating II — a lens-coating nanotechnology employing a super-low refractive film fabrication process.
By coupling this advanced lens coating with the high-grade, multi-layer HD Coating, which reduces average reflectance in the visible ray spectrum to less than 50% of conventional multi-layer coatings, the lens effectively reduces flare and ghost images to a minimum, even in demanding lighting conditions such as backlighting.
Developed as an All Weather (AW) model, the lens features a dependable dustproof, weather-resistant structure with eight special seals to prevent the intrusion of water and dust into the lens interior. When paired with a PENTAX dustproof, weather-resistant digital SLR camera body, it forms 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. It also responds to the exacting demands of professional photographers: its focus ring is ideally shaped to assure firm hold and error-free focusing operation even with a wet or gloved hand; it provides dependable operation at a temperature from -10°C to 40°C; and it features the high-rigidity lens barrel structure required for field photography.
In order to shift the heavy, rear focus-lens group more smoothly and efficiently during focusing operation, the lens features a newly developed ring-type ultrasonic wave motor SDM, which generates as much as 7.5 times the torque of the compact SDM installed in existing DA★-series lenses. Thanks to this enormous driving power, the lens assures high-speed, high-precision autofocus operation. Because of minimal backlash of the focus ring, it also provides responsive manual-focus operation.
The lens barrel has been designed for a superior appearance. It features a panel line accentuated with the leveled construction of parts, and a uniformly designed body line all the way to the exclusive flower-shaped lens hood. Including the gold line symbolic of the Star-series lens and the familiar deep-green ring — a trademark of PENTAX interchangeable lenses — the lens is in keeping with a design concept standardized for both color scheme and parts positioning. This design concept will be applied to future Star-series lenses, as a reminder of the consistency and dependability of the PENTAX Star series.