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
RICOH IMAGING COMPANY, LTD. is pleased to announce the launch of the HD PENTAX DA645 28-45mmF4.5ED AW SR. 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.
Main 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, including exaggerated perspective and expanded depth-of-field, this lens can be used for a wide variety of scenes and subjects, such as sweeping landscapes and cramped rooms, adding more versatility to advanced medium-format digital SLR photography.
2. State-of-the-art optical design to optimize super-high-resolution images captured by medium-format digital SLR cameras
Designed as the HD PENTAX DA-series model in the PENTAX 645 lens series, this lens’s image circle is optimized for the image sensor of the PENTAX 645Z camera body. Its optics consists of 17 elements in 12 groups, including two high-performance aspherical elements and two ED (Extra-low Dispersion) elements, to enhance image resolution and brightness at edges, while minimizing various aberrations. Coupled with innovative lens coatings and an anti-reflective coating applied to the interior of the lens barrel, this lens is designed to bring out the best performance of medium-format digital SLR cameras.
3. HD Coating and Aero Bright Coating to optimize light transmittance and minimize reflection
This lens is treated with the high-grade, multi-layer HD Coating* to optimize light transmittance and minimize reflection. This coating delivers sharp, clear images free of flare and 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 is designed to assure exceptionally high light transmittance and super-low refraction.
* HD stands for High Definition.
** A PENTAX-original lens coating process developed through the use of nanotechnology. Using a silica aerogel with a uniform porous structure as the base material, this coating produces clear, high-quality images by assuring outstanding anti-reflection performance over a broad wavelength range.
4. PENTAX-original, lens-installed SR mechanism
This lens incorporates the PENTAX-innovated SR (Shake Reduction) mechanism within the lens barrel. Since this mechanism effectively compensates for camera shake up to approximately 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.
* In compliance with CIPA standard (f=45mm, using PENTAX 645Z/645D)
5. Dependable dustproof, weather-resistant construction
As the newest member 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 and water into the lens interior. By mounting this lens on the PENTAX 645Z camera body, the user is assured of a durable, reliable digital imaging system that performs superbly in demanding shooting settings — even in rain or mist, or in locations prone to water splashes or spray.
6. Other features
・SP (Super Protect) Coating applied to the front surface of the lens to effectively repel water and grease
・Rounded diaphragm to produce a smooth, beautiful bokeh (out-of-focus rendition), while minimizing the streaking effect of point light sources
・Smooth, quiet autofocus operation driven by a built-in DC motor
・Quick-Shift Focus system for instant switching to manual-focus operation after the subject is captured in focus by the camera’s AF system
・Various filters such as the C-PL (circular polarizing) filter can be attached to the front lens – a very unique feature for a wide-angle lens.
