The HD PENTAX-D FA 21mm f/2.4ED Limited DC WR Lens from Pentax provides an ultra wide-angle field of view on K-mount full-frame DSLR cameras. An ideal lens for architectural and landscape photography, this lens provides you with a sophisticated optical design for outstanding sharpness and even illumination. The broad 92° angle of view is well-suited to all-around shooting for both interior and exterior locations. When used for distant subjects such as landscapes, it assures solid, uniform image rendition across the image field and delivers sharp, clear, high-resolution images. Contrasting the broad, wide-angle perspective is a close-focusing system that provides a minimum focusing distance of 7.1" along with a 0.26x maximum magnification for working with nearby subjects. Its f/2.4 maximum aperture allows for working in low-light conditions and also affords greater control over depth of field for isolating subject matter. An eight-blade rounded diaphragm also contributes to a smooth and pleasing bokeh quality. This lens also features a high-grade HD coating for exceptional image rendition, which controls ghosting and flare to realize high contrast imagery with accurate, neutral color balance, plus protective SP coating on the front lens surface to repel dust, stains, and debris. Additionally, the barrel, hood, and cap are all made of high-grade aluminum, meticulously machined for an attractive appearance and beautiful texture. Exceptional Optics Four ED (Extra-Low Dispersion) glass elements and a single Super ED glass element minimize chromatic aberration and prevent color bleeding, not only in the main focus area, but also in the surrounding defocused areas. The lens 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. High-Definition Coating PENTAX-original HD coating is a high-grade, multi-layer coating that reduces the average reflectance in the visible spectrum to less than 50 percent, effectively minimizing flare and ghost images in demanding lighting conditions and backlighting. Electromagnetic Diaphragm Mechanism 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. Additional Features Ultra wide-angle 21mm lens is designed for full-frame Pentax K-mount cameras, however, can also be used with APS-C models where it will provide a 31.5mm equivalent focal length. SP (Super Protect) Coating keeps the front surface of the lens free of dust or stains. Built-in motor to drive the AF mechanism for smooth, quiet autofocus operation. Eight-blade circular diaphragm produces beautiful light beams with pointed light sources and creates a natural, beautiful bokeh 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.
