Thanks to the incorporation of PENTAX-original HD Coating — a newly developed, high-grade multi-layer lens coating — & the PENTAX-innovated, lens-installed SR (Shake Reduction) mechanism, this medium-telephoto lens assures bright, velvety image description that is ideal for portrait photography. Velvety image description ideal for portraiture When mounted on a PENTAX 645D medium-format digital SLR camera body, this medium-telephoto lens offers a focal length of Approx. 71mm (or Approx. 65mm when mounted on a PENTAX 645 film-format camera body) in the 35mm format. By incorporating two ED (extra-low dispersion) elements & one glass-moulded aspherical element in its optics, it assures high-resolution image reproduction over the entire image field, while effectively minimizing chromatic aberration, a problem commonly associated with fast lenses. At larger apertures, this lens defines the subject with fine, delicate lines & soft, velvety edges. Coupled with a beautiful bokeh (out-of-focus rendition) effect created by a very shallow depth of field, it is an ideal lens for portrait photography. At smaller apertures, it produces sharp, solid images to make it useful for applications other than portraiture, such as scenic & still-life photography. It also offers macro photography at a maximum magnification of 0.5 times. In close-up applications, its floating mechanism effectively compensates for the curvature of the field to assure sharp, well-defined images. New HD Coating & Aero Bright Coating. This lens is treated with a newly developed, high-grade multi-layer lens coating called HD Coating.* Compared with conventional multi-layer coatings, this new coating offers higher light transmittance with reduced reflection, to deliver sharp, clear images free of flare & ghost images, even under demanding lighting conditions such as backlight. By coupling this coating with the PENTAX-exclusive, high-grade Aero Bright Coating, ** this lens optimizes light transmittance while minimizing refraction. * HD stands for High Definition, & signifies the lens’s capacity to reproduce images that excel in transparency, definition, resolution & rendition. ** A PENTAX-original lens coating process developed through the use of advanced nanotechnology. Using a silica aerogel with a uniform porous structure as the base material, this coating produces clear, high-quality images by assuring an outstanding anti-reflection performance over a broad wavelength range. PENTAX-original, lens-installed SR mechanism This is the first lens to incorporate the PENTAX-innovated SR (Shake Reduction) mechanism within the lens barrel. Since this mechanism effectively compensates for camera shake up to Approx. 3.5 shutter steps, the user is assured of sharp, blur-free images even under conditions prone to camera shake, such as when handholding the camera at poorly lit locations without flash illumination, or when photographing sunset scenes. Dustproof, weather-resistant construction As a new model of the AW (All Weather) series, this lens features a dependable dustproof & weather-resistant construction with 11 special seals to effectively prevent the intrusion of dust & water into the lens interior. By mounting this lens to a PENTAX 645D camera body, the user is assured of a durable, reliable imaging system that performs superbly in demanding outdoor settings — even in rain or mist, or at locations prone to water splashes or spray. New exterior design signifying HD series While inheriting traditional design features of PENTAX medium-format lenses, such as a twill-patterned focus ring & metal rings, this lens features a red almite ring at the front end of the focus ring to signify the new HD PENTAX lens series & enhance its exclusive appearance.