The Horseman 90mm f/6.8 Grandagon-N Lens is a Rodenstock 90mm f/6.8 Grandagon-N with a standard Copal #0 shutter, but built into a Horseman-specific helical focusing mount and barrel assembly made to fit upon their SW617 Professional medium format panoramic camera. It provides an extremely wide angle perspective on the 617 Professional that's roughly equivalent to the view of a 22mm lens in 35mm terms. A built-in lens guard helps protect the sensitive optics. For critical work with transparencies, the optional Rodenstock #170002 center filter (B&H code "ROCF67") is highly recommended.
The 90mm f/6.8 Grandagon-N is a highly-corrected 6-element lens design with an f/16-22 recommended working aperture. It can focus down to 3.6' (1.1m) with the 617 Professional camera.
| Optical Construction | 6 elements in 4 groups |
| Closest Focusing Distance | 3.6' (1.1m) |
| Aperture Range | f/6.8-f/45 |
| Covering Power | 102° |
| Image Circle @ Infinity | 221mm diameter @ f/22 |
| Shutter | Copal #0 |
| Shutter Speed | 1/500th to 1 Second plus B & T |
| Filter Size | 67mm EW |
| Weight | 2.6 lbs (1.20kg) |