The Rodenstock 23mm f/5.6 HR Digaron-S Lens is a super wide angle large format lens specifically designed for use with digital backs, which require a smaller image circle with extreme resolution, color correction, and maximum performance at a large aperture. This lens is recommended for use with backs having a 33 x 44mm maximum image area, and upon such a back it would provide a view similar to that of a 18mm lens upon a 35mm format camera. This HR Digaron-S is delivered in a standard type Copal #0 shutter.