In conjunction with its announcement of the 645D medium format camera, Pentax has announced the smc D FA 645 55mm F2.8 AL[IF] SDM AW lens. First in the D FA 645 lens series, this weather-resistant prime lens features a Supersonic Direct-drive Motor (SDM) autofocus drive and Quick-Shift for instant AF/MF switching. It is also the company's first 645 system lens to incorporates a rounded diaphragm.The 55mm lens will be available alongside the 645D camera at a suggested retail price of ¥100,000 (~ US $1,100).

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smc PENTAX-D FA 645 55mmF2.8 AL[IF] SDM AW
A Unifocal Standard Lens for use with Medium-Format Digital SLR Cameras

The First Model of the smc PENTAX-D FA 645 Series

March 2010: HOYA CORPORATION PENTAX Imaging Systems Division is pleased to announce the launch of the smc PENTAX-D FA 645 55mm F2.8 AL[IF] SDM AW. Developed as the first model of the PENTAX-D FA 645 lens series, it not only features new optics optimized for high-quality digital photography to assure exceptional image-description performance, but also provides an image circle covering the image area of existing 645-format film SLR cameras. This unifocal standard lens also comes with a dependable, dust-proof, weather-resistant construction for active outdoor photography.

Major Features
State-of-the-art optics to accommodate the requirements for super-highresolution photography using medium-format digital SLR cameras Incorporating high-performance, hybrid aspherical optical element in its optics, this new standard lens offers exceptional image-resolving power with outstanding brightness levels even at the edges, while compensating various aberrations to a minimum. All lens characteristics are optimized for digital photography: for instance, flare and ghost images are minimized by applying exclusive lens coatings to optical elements and employing anti-reflection materials for the interior of the lens barrel. As the result, this lens can bring out the full potential of the PENTAX 645D medium-format digital SLR camera.

Versatile standard lens
When mounted on the PENTAX 645D camera body, this standard lens offers a focal length of 43.5mm (in the 35mm format), which produces an angle of view close to that of the human eye. As the result, it can be used for many different kinds of subjects and applications, including landscapes and portraits.

Dependable dustproof, weather-resistant construction
Using seven special seals, the lens’ dustproof, weather-resistant construction effectively prevents the intrusion of dust and water to the lens interior. By coupling this lens with the PENTAX 645D camera body, the user is assured of a durable, reliable digital SLR camera system that performs superbly in outdoor settings, even in rain or mist or at locations prone to water splashes or spray. PENTAX plans to use the “AW” (All Weather) designation in the product name of all dustproof, weather-resistant medium-format interchangeable lenses to be marketed in the future.

Aero Bright coating to dramatically improve image description in backlight
The lens is treated with PENTAX-original Aero Bright coating, which delivers brilliant, high-quality images by preventing annoying flare and ghost images more effectively than ever before. Born as the fruit of PENTAX’s advanced nanotechnology, this exclusive coating effectively reduces lens reflectance and greatly increases light transmittance by forming a silica aerogel layer with uniform pores on the surface of optical element.

Rounded diaphragm to produce a beautiful bokeh
This is the first PENTAX medium-format interchangeable lens to features a completely rounded diaphragm. It creates a natural, beautiful “bokeh” (out-of-focus rendition), while minimizing the streaking effect of point light sources.

Smooth, quiet SDM autofocus mechanism

The SDM (Supersonic Direct-drive Motor) autofocus mechanism operates smoothly and quietly using the supersonic motor installed inside the lens barrel.*

SP coating to block dust and dirt
The front surface of the lens is treated with PENTAX-original SP (Special Protect) coating, which applies an exclusive fluorine compound to the lens surface through a vapor deposition process. This SP coating not only effectively repels dust, water and grease, but also makes it easy to wipe off fingerprints and cosmetics.

Other features

  • Image circle covering the image area of 645-format film SLR cameras
  • Functional, simplified design, with no aperture ring
  • Quick-Shift Focus system for instant switching to manual-focus operation, after the subject is captured in focus by the AF system
  • PL filter window for easy installation of a polarizing filter without removing the lens hood
  • PH-SA67 Square Plastic Hood (optional)** for more effective prevention of flare and ghost images when mounted on the PENTAX 645D camera body

*Only manual-focus operation is available when this lens is mounted on the PENTAX 645N or PENTAX 645N II camera body.
**This hood cannot be used with a 645-format film SLR camera body, as it causes vignetting.

smc PENTAX-D FA 645 55mmF2.8 AL[IF] SDM AW specifications

Focal length 55mm
Diagonal Angle of view (APS-C) 53º
Maximum aperture F2.8
Minimum aperture F22
Lens Construction

9 elements / 7 groups

Number of diaphragm blades 9, rounded
Minimum focus 0.5m
Maximum magnification 0.17x
AF motor type • Supersonic Drive Motor (SDM
• Quick Shift manual focus
Filter thread 67mm

146g (14.7 oz)

Dimensions 81.3mm diameter x 68.2mm length
(3.2 x 2.7 in)
Lens Mount Pentax 645KAF2