The HD PENTAX-DA645 28-45mm f/4.5 ED AW SR Lens from Pentax provides users of the 645D or 645Z with a weather-resistant, ultra wide-angle zoom lens with a 35mm equivalent focal length of 22-35.5mm. This lens features the 645AF2 mount for electronic aperture control and autofocus with an internal DC motor. Also, it has a constant maximum aperture of f/4.5 throughout its zoom range and uses extra-low dispersion glass elements to limit the effects of chromatic aberrations and improve sharpness.
The dustproof and weather-resistant 28-45mm lens features a quick-shift focus system that allows users to quickly switch from auto to manual focus as well as shake reduction image stabilization good for up to approximately 3.5 stops. Further improving image quality is the use of HD and Aero Bright coatings that reduce flare and ghosting. A Super Protect coating on the front element is also utilized to ensure the surface is free of dust and marks.
This lens has nine rounded aperture blades that will provide smooth out-of-focus areas. Additionally, the lens has an 82mm front filter thread and comes with both a case and hood.
Aperture range from f/4.5 to f/32
Pentax 645AF2 mount for full electronic aperture control and autofocus with an internal DC motor
Lens construction features 17 elements in 12 groups
Maximum magnification of 0.21x
All-weather design is both dustproof and water-resistant
Built-in shake reduction technology provides about 3.5 stops of image stabilization
Nine rounded diaphragm blades provide a circular aperture from f/4.5-6.3 at 28mm and from f/4.5-8 at 45mm
Minimum focusing distance of 1.3'