This wide-angle zoom lens, with an aperture range of f/4.5 to f/32 and 35mm equivalent focal length of 26mm to 43.5mm, is built for use with medium-format PENTAX 645 mount cameras. Addressing common wide angle issues, two aspheric aspects significantly reduce distortion, field curvature, and common aberrations. High-refraction and low-dispersion glass, a three-group floating zoom, and 0.4m minimum focus distance assist with maintaining image quality. It features an 82mm front filter thread and an eight-blade diaphragm to balance out-of-focus spots.