Exclusive Limited-series quality with optimized image rendition and fine texture description
True to the Limited series design concept, this lens was developed to provide a distinctive visual expression. This could be achieved only by conducting a series of image quality assessments using a vast number of captured images, and by feeding the results back into the design process, along with various numerical evaluations using measuring instruments.
When used for distant subjects such as landscapes, it assures solid, uniform image rendition across the image field. By further closing the aperture down, it delivers sharp, clear, high-resolution images, even at the edges. Its optical characteristics change for close-range photography. At open aperture, it provides a mild bokeh (defocused) effect in the background while capturing the main subject in sharp, crisp focus. This lets you make the subject stand out against a defocused background, with the exaggerated perspective typical of ultra-wide-angle lenses. At a minimum focusing distance of 18 centimeters, it can create a variety of visual expressions, depending on the subject being captured.
To create a more attractive exterior design, the lens barrel, hood and cap are meticulously machined from high-grade aluminum. In every way, this lens is an exceptional image tool that brings greater joy and inspiration to your photography.
Exceptional optics incorporating the latest optical technologies
The lens optics incorporates four ED (Extra-low Dispersion) glass and one Super ED (Extra-low Dispersion) glass optical elements to minimize chromatic aberration and prevent color bleeding, not only in the main in-focus area, but also in the surrounding defocused areas. It also features a large-aperture negative meniscus optical element, a biconvex aspherical glass-mold optical element, and a high-refraction glass optical element in the first lens group, to reduce the overall size despite the ultra-wide-angle design, while delivering outstanding imaging performance for sharp, crisp images without fuzziness, even in the peripheral areas.
The lens also features PENTAX-original HD Coating. Compared with conventional multi-layer coatings, this high-grade, multi-layer coating reduces the average reflectance in the visible spectrum to less than 50 percent, effectively minimizing flare and ghost images even in demanding lighting conditions such as backlighting.
Electromagnetic diaphragm mechanism for high-precision exposure control
This lens incorporates an electromagnetic diaphragm mechanism* to assure high-precision exposure control when used in combination with compatible digital SLR cameras. It assures smooth, worry-free video shooting in locations prone to considerable brightness changes, such as a stage with rapidly changing lighting conditions, or a forest with filtering sunrays.
Dependable weather-resistant construction
For use in demanding conditions -- such as at waterfronts or in sudden rainfall -- the lens features a dependable weather-resistant construction. By pairing it with a PENTAX weather-resistant digital SLR camera body, the user can create a highly dependable, airtight digital imaging system that performs superbly even in the most demanding shooting locations -- in rain or mist, or at locations prone to splashing water.
Other Features:
- SP (Super Protect) Coating to keep the lens front surface free of dust or stains
- Built-in motor to drive the AF mechanism for smooth, quiet autofocus operation
- Eight-blade circular diaphragm to produce beautiful light beams with point light sources, while creating a natural, beautiful bokeh (defocus) effect at open and larger apertures
- QFS/A (Quick-Shift Focus System) for instant shift to the manual-focus mode without requiring focus-mode switching operations, after the subject has been captured in focus by the camera's autofocus system
