The Rodenstock 40mm f/4 HR Digaron-W Lens is a wide angle 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 40 x 54mm maximum image area, providing a view similar to that of a 26mm lens on a 35mm format camera.
The included Rollei Electronic #0 Shutter delivers precision exposure control with speeds ranging from 1/500 - 30 sec, plus B, and allows f/stop adjustments in as little as 1/10 increments. Aperture and shutter speed are controlled via a Rollei Lens Control unit (purchased separately).
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 digital-specific lenses such as this HR Digaron-W 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 HR Digaron-W, you can use digital backs with a pixel pitch as small as 5µ.
Despite this lens' short focal length, it provides an adequate 69.5mm flange focal length with 25.1mm of space between the rear of the barrel and the image receiving area, permitting its unrestricted use on nearly any camera which accepts a medium format digital back.