The Rodenstock 135mm f/5.6 Apo-Sironar digital Lens is a short telephoto 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 upon such a back similar to that of a 54mm lens upon a 35mm format camera.
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. Given its 150mm focal length (which allows plenty of space) and because it benefits from superior optical design without any needed concessions for an SLR camera's mirror box, this 150mm Sironar's commonly adapted for use with DSLR cameras as a specialist for portraiture and products. Its remarkable resolution can produce results impossible to achieve with an SLR system lens.