Schneider Optics PC-SUPER-ANGULON 28 mm f/2.8 Camera Lens User Manual


 
8 LargeImageCircleforLensShiftsupto1¡mm
The PC-SUPER-ANGULON 28 mm f/28 already produces an exceptionally
attened image at full aperture within the 62 mm image circle which is thus
twice as large in area relative to the image circles of other 35 mm lenses
Sharpness and contrast are increased further in the central area used with-
out shift by stepping down slightly to f/4 to f/56 Sharpness, contrast and
brightness naturally drop outside this area due to the huge image angle
with an open aperture The full aperture with a decentered lens is there-
fore only intended for the image composition and the focusing A good im-
aging performance is obtained at the edge when stepping down further in
dependence on the adjustment path; an aperture of ¡1 is recommended at
maximum shift Distortion and vignetting are exceptionally low
While the image quality falls considerably in the close range with many
wide-angle lenses, the good imaging properties of this lens are maintained
thanks to “oating elements” (a distance-coupled axial shift of a lens ele-
ment group relative to the remaining system) This makes this lens very in-
teresting eg for model shots
The adjustment takes place at a shifting knob on a exible shaft which is
easy to grip and sensitive in operation Millimeter scales on mutually oppo-
site sides allow comfortable reading in any shifting knob position Since the
shift is possible at both sides of the zero position, the most favorable ori-