Special Features - Leica SUMMARIT-S 1:2.5/35mm ASPH. Notice D'utilisation

Special features

The LEICA SUMMARIT-S 35mm f/2 .5 ASPH is a lens designed for the Leica S SLR system .
Due to the 30x 45 mm sensor size of the Leica S cameras it is comparable to a focal length of
28mm with 35mm format systems .
The LEICA SUMMARIT-S 35mm f/2 .5 ASPH delivers maximum contrast and resolution even
with at full stop and from infinity to the close-up range. The slightly lower contrast in the ex-
treme corners of the image at full stop can be eliminated by stopping down slightly, and the
reproduction of tiny details at the very shortest range can be improved in the same way . In
addition, the lens is almost free of aberrations and there are practically no monochromatic
aberrations (curvature of field, astigmatism, coma). The incidence of chromatic aberrations is
minimal and the secondary spectrum is also corrected out stand ingly well .
The vignetting, characteristic of any optical system, is a maximum of 1 .4 stops at full stop
in the infinity setting. Stopping down to 5.6 reduces it to the natural vignetting only. The
maximum distortion is very low at just 1.2 % in the infinity setting and in practical terms is
only perceptible in the image with exceptionally critical subjects . Even at the shortest range,
distortion remains low at 1.7 %, so that there is no need to worry about negative effects on
your pictures .
A total of 11 lenses are used to achieve this exceptional performance. They include five made
of glass types with anomalous partial dispersion - three of these are fluoride lenses with ex-
ceptionally low dispersion to correct any chromatic aberrations . Two aspherical lenses are
used to minimize monochromatic aberrations, with the one in the front group also ensuring
the excellent distortion correction .
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