The new HD Pentax-DA645 28-45mm f/4.5 ED AW SR lens is a weather-resistant, ultra wide-angle zoom lens for Pentax 645 cameras, with a 35mm equivalent focal length of 22-35.5mm.

It features the 645AF2 mount for electronic aperture control and autofocus with an internal DC motor. It has a constant maximum aperture of f4.5 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 stabilisation good for gaining an extra 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 ensures 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.

Key features:
Aperture range from f4.5 to f32;
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 stabilisation;
Nine rounded diaphragm blades provide a circular aperture from f4.5-6.3 at 28mm and from f4.5-8 at 45mm;
Minimum focusing distance of around 40cm.