The lens series HR Digaron-S includes six high-performance lenses optimized for digital photography and provides with a focal length range from 23 mm to 180 mm and an image circle diameter of 70 mm* (80 mm for the 180 mm lens). These lenses are far beyond common quality standards and come very close to the theoretical ideal of diffraction limited image sharpness – even for open aperture. In order to stop down the HR-lens as little as possible (to avoid diffraction blur!), the increase in depth of field by lens swing and tilt should be used for taking images of subjects of a large depth with an adjustable technical camera.
* Tilt and shift lenses for 35 mm SLR cameras have an image circle diameter of about 58 mm and therefore allow only shift and tilt movements which are half as large and often insufficient for architecture or product images.
The HR Digaron-S allows without any restrictions all possible camera movements of analog photography for sensors up to 33 x 44 mm. The image circles and camera movements must be adapted to smaller sensor formats proportionally to the format diagonal. In landscape and product photography, where often a reduced camera movement is sufficient, the HR Digaron-S can be applied even for a 37x49 mm sensor. As shown by the MTF-curves, even at the image corners sharpness is high enough to utilize the resolution power of the highest-performance sensors with up to 60 megapixels and a pixel pitch of only 6 µm (therefore we indicate the MTF for max. 80 line pairs per millimeter). An image quality almost impossible up to now is realized due to perfect correction of curvature of field, integration of the 2 mm thick sensor cover glass into the optical calculation and excellent correction of chromatic aberration in order to avoid color fringes.
The wide angle lenses of 35 mm, 28 mm und 23 mm focal length are provided with larger flange focal lengths and larger flange to lens end distance in order to avoid mechanical problems when using extreme parallel lens shift or swing and tilt movements. For most of the cameras this is possible even with a flat lens board. Consequently, there is no more limit for the shutter choice – also the Rollei-Electronic-Shutter, which is too large for recessed lens boards, is suitable. Furthermore, the steeper light incidence at the image corners caused by the longer distance, avoids additional vignetting of extreme wide-angle images due to microlenses in front of the light-sensitive pixel plane.
The new Rodenstock HR Digaron-S 23 mm f/5.6 is the first super wide-angle lens providing a large image circle of 70 mm allowing its use with nearly all types of technical cameras. Especially photographers of (interior) architecture or landscapes, who had to use analog film for extreme image angles until now, will be highly impressed by this lens. With the 37 x 49 mm sensor the focal length of this lens corresponds to a focal length of 16 mm for a 24 x 36 mm sensor.