The Apo-Grandagon series incorporate new glass combinations including ED(Extra-low Dispersion) glasses making apo-chromatic correction of super-wide angle lenses possible for the first time.
The high maximum aperture of f/4.5 makes adjustments easier, and the working aperture of f/11-16 allows shorter exposure times for outdoor work. The use of an optional Rodenstock center-filter is recommended for critical work. This lens is mounted on a matched focusing mount with a mounting plate specific to the Horseman SW612 and SW612 Pro cameras.
Focal Length Equivalents:
55mm lens/6x12cm format = 20mm lens on the 35mm format
55mm lens/6x9cm format = 26mm lens on the 35mm format
55mm lens/6x7cm format = 31mm lens on the 35mm format