"HD PENTAX-DA645 28-45mmF4.5ED AW SR: An ultra-wide-angle zoom lens designed to optimize the optical performance of the PENTAX 645Z, and usable on all PENTAX medium-format digital SLR cameras This ultra-wide-angle zoom lens is the latest addition to the PENTAX 645 interchangeable lens series, designed for exclusive use with PENTAX medium-format digital SLR cameras. Providing focal lengths from 22mm to 35.5mm in the 35mm format, this is exclusively designed for digital imaging. Its image circle is optimized for an image sensor of the new PENTAX 645Z medium-format digital SLR camera (launched on June 27), and a number of PENTAX-developed technologies including advanced lens coatings are incorporated, to deliver super-high-resolution images made possible only by medium-format digital SLR cameras. Thanks to its dustproof, weather-resistant construction, this lens also offers outstanding reliability and durability even under demanding shooting conditions, allowing the photographer to capture various outdoor images, such as sweeping landscapes, without worries. Major Features 1. First ultra-wide-angle zoom lens for use with medium-format digital SLR cameras This zoom lens offers a zoom ratio of approximately 1.6 times to cover ultra-wide-angle to wide-angle ranges (for focal lengths of 22mm to 35.5mm in the 35mm, when mounted on a PENTAX 645Z or 645D camera body). With visual effects unique to wide-angle lenses, inc|Fast f/4.5 aperture for outstanding depth of field control|Ultra-wide-angle Zoom - ideal for landscapes and architecture.|Quick-shift Focus System allows instant switching from auto to manual focus|Rounded diaphragm blades create a beautifully, smooth bokeh at large aperture settings|New HD Coating and Aero Bright Coating to optimize light transmission and minimize reflection|PENTAX-original, lens-installed SR mechanism compensates up to 3.5 stops|Focal length equivalent to 22-35.5mm (in 35mm format)|Dustproof, weather-resistant construction and Super Protect (SP) Coatings provide optimal protection|PENTAX-original, high-grade multi-layer HD (High Definition) Lens Coating provides sharp, clear images - free of flare and ghosting|Lens design allows filters to be attached without obstruction.|Lens hood specifically optimized to image circle and zoom range"