The optical construction of the Irix Blackstone wide-angle lens is superb, meeting the most demanding requirements of modern cameras. 15 elements in 11 groups include three elements of highly refractive glass and two of extra-low dispersion glass. Two aspherical lenses provide extremely high image quality and improve image brightness at the edges, while minimizing distortion and aberration.
With a minimum focusing distance of 0.28 metre (0.92 ft) and 9 rounded shaped aperture blades, the lens stands for supremely smooth out-of-focus areas.