The Rodenstock 55mm f/4.5 Apo-Sironar digital Lens is a 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 maximum image area of 72 x 96mm, capturing a view similar to that of a 20mm lens on a 35mm format camera. This Apo-Sironar digital is delivered in a standard type Copal #0 shutter.
In many cases, digital photography is superior to conventional photography if the desired end product is a printed image. To achieve this ideal, however, a much higher demand is made upon the image reproduction quality of the lens. This is because of a digital image chip's smaller area, which means finer details in a scene are squeezed into a smaller image recording area, as well as their sensitivity to color fringes.
But Rodenstock's digitally-specific lenses such as this Apo-Sironar digital provide image quality which allows the maximum capacity of a digital back to be realized. The lens utilizes every technological possibility to get as close as possible to the absolute limits of diffraction-determined resolution, even accounting for the properties and thickness of a CCD's protective glass. With the Apo-Sironar digital, you can use digital backs with a pixel pitch as small as 5µ.
This lens is recommended for use at apertures of f/8-11; you should primarily use your camera's movements to control the depth of field.