The Horseman 24mm f/5.6 Apo-Digitar Lens Unit for SW-DII Pro is a Schneider 24mm Apo-Digitar with a standard Copal #0 shutter, but built into a Horseman-specific helical focusing mount and barrel assembly made to fit upon their SW-DII Pro camera. It is the widest lens available to the camera, and for critical work it is highly recommended to use the optional Horseman #28991 center filter (B&H code "HOFC24AD").
The 24mm Apo-Digitar is one of the world's widest large format lenses made specifically for the demands of digital photography, where absolute performance across a smaller image area are needed. The Apo-Digitar delivers, giving extremely high contrast and resolution from the center to the edge of the field, without color fringing or distortions that would otherwise limit the higher resolving capacity of medium format digital backs.