The pixel size of digital sensors cannot be reduced at will without an increasing image noise and decreasing dynamic range. For this reason, larger sensors for professional Digital backs providing for an ultimate resolution (currently up to approx. 60 megapixels) have been developed. The digital lenses, designed for smaller sensor formats, with an image circle around 70 mm, do not allow hardly any camera movement when applying such large sensors. That is why Rodenstock developed the HR Digaron-W lens series with image circles from 90 mm up and an almost diffraction limited high resolution.The image angle of the HR Digaron-W 40 mm f/4 with a 37x49 mm sensor corresponds to that of a 28 mm lens for 24x36 mm sensors; with a 40x54 mm sensor it even corresponds to that of a 26 mm lens. Its back focal length of approx. 25 mm leaves free space between the rear mount and the sensor for shift and tilt movement without touching the sensor or the rear standard. The flange focal length of approx. 70 mm allows focusing at infinity for all technical cameras with a flat lens board, which makes it much easier to set the aperture and the shutter speed and permits the use of the Rollei Electronic shutter. The retro-focus design causes a steeper light incidence at the margin. So the further fall-off in illumination, which is inevitable when using microlens sensors, can be avoided.