The image angle of the new HR Digaron-W 40 mm f/4 corresponds to that of a fictitious 26.5 mm lens for 24x36 mm sensors. The HR Digaron- W 40 mm f/4 is outstanding for the following features:
• The back focal length of approx. 25 mm leaves free space for shift-and-tilt movement between the rear mount and the sensor, 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 micro lens sensors, can be avoided.
• No vignetting occures already for an aperture of 5.6.
• The optical effect of the sensor cover glass has been taken into account in the optic calculation for eliminating its spherical and chromatic aberration, as well as its astigmatism.
• The high tech multi-coating provides for ultimate transmission, excellent contrast and freedom of ghost and flare.
Image Circle at infinity - 90mm @ f11 - covers 40x54mm sensor
This allows shift of up to 16mm vertically and 13mm horizontally on a 40x54mm sensor
Flange to focal distance at infinity - approx. 70mm in Copal shutter
Filter Size - 67mm
Weight - 600g in Copal shutter