Photography / News

Unveiled: Wide-Angle Zoom Lens for the Pentax 645


Ricoh Imaging is expanding the reach of the Pentax 645 zoom lens lineup with the release of the HD PENTAX-DA645 28-45mm f/4.5 ED AW SR Lens for the 645D and 645Z cameras. The wide-angle lens provides a 35mm equivalent focal length of 22-35.5mm and a constant f/4.5 aperture, exceptionally useful when shooting in cramped spaces or when you can’t achieve an ideal position. It also has Shake Reduction image stabilization and a variety of other technology to get you the best results no matter where you end up.

Unique to Pentax’s medium-format lenses is the inclusion of a shake reduction image stabilization mechanism. This system compensates for approximately 3.5 stops of light, further enhancing a photographer’s ability to shoot in less-than-ideal situations.

A welcome feature for outdoor shooters is an all-weather design that matches the dustproofing and water resistance of Pentax’s medium-format digital cameras. Take the lens on your most daring adventures and don’t worry about getting just a couple inches closer to that waterfall. The lens’ front element has a Super Protect coating that makes it easier to clean off dust and water. You may also use 82mm threaded filters, such as UV, neutral density, and polarizers.

Featuring the 645AF2 mount, the lens is fully compatible with the 645Z and 645D digital cameras but not the older film models. This system enables electronic aperture control as well as fast and silent autofocus courtesy of an in-lens DC motor. There is a Quick-Shift Focus System which allows you to alternate between manual and auto with the flip of a switch. Additionally, nine rounded aperture blades create a circular diaphragm for smooth, natural-looking out-of-focus areas.

By necessity, medium-format lenses are designed to hold up to the demands of high resolution imaging.

The 28-45mm lens utilizes extra-low dispersion glass elements as well as unique coatings for clear images that are free of aberrations. The ED glass increases image sharpness while the Aero Bright and HD coatings reduce reflections to allow more light to reach the sensor. Also, the design of the lens’ front element reduces vignetting by extending within the hood at 28mm and retracting when at 45mm.

HD PENTAX-DA645 28-45mm f/4.5 ED AW SR Lens
Lens Mount Pentax 645AF2
Focal Length (35mm Equivalent) 22-35.5mm
Maximum Aperture f/4.5
Minimum Aperture f/32
Angle of View 89-63°
Minimum Focusing Distance 1.3' (0.4 m)
Autofocus Motor In-lens DC motor
Image Stabilization Yes, Shake Reduction
Weather Resistant Yes
Magnification 0.21x
Lens Construction 17 elements / 12 groups
Diaphragm Blades 9
Rounded: f/4.5 to f/6.3 at 28mm; f/4.5 to f/8 at 45mm
Filter Ring Diameter 82mm
Dimensions 3.9 x 6.0" (99 x 151.5 mm)
Weight 3.2 lb (1.5 kg)
Compatibility Pentax 645Z and 645D

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Give me one reason to buy this lens when Canon 24-105 mm/F4.0 (L) is available for US$2,800 and Canon 24-70mm/F2.8 at US$3,300. I have both lenses and they are indeed best of breed in their class.

You own a Pentax 645 camera and Canon lenses dont fit.

(1) There isn't a comparison (yet) between the smaller sensors and larger sensors in many situations.  A Canon 5dsr will blow whites in landscapes considerably quicker than a larger Medium Format CMOS sensor; easily detectable in landscapes as the color range is noticeably smaller on the Canon.  

(2)  if you're talking about a smaller resolution Canon body; there's just no comparison to a 50mp medium format CMOS sensor.

(3) the lens is slightly wider when you do the math, and the medium format aspect ratio is arguably more pleasing to most professionals and clients alike.

(4) what 50mp Canon camera, as of 2016, can reasonably shoot at 12,800 ISO, and comfortably shoot at 6400 ISO? ...exactly.  I rest. ;)