Leica SUMMARIT-S 1:2.5/35mm ASPH Instructions Manual page 16

For focusing, only the rear assembly made up of 6 lenses is moved, which means that the
total length of the lens does not change .
Summary: The LEICA SUMMARIT-S 35 mm f/2 .5 ASPH provides exceptional imaging
per formance from the infinity setting to the close-up range, at full stop and when stopped
down . This outstanding performance right up the maximum close-up range gives the photo-
grapher a unique choice of compositional options without having to accept any compromises
in image quality .
Design of Leica S lenses
In principle, all Leica S lenses have the same design: There is an external bayonet (2b) for the
lens hood (1) and an internal thread (2a) for filters on the front mount, a setting ring for the
distance (3), a window (4) for reading the distance scale (4b) underneath and a fixed ring (5)
with a red alignment button for changing lens (5a) .
In the bayonet flange there is a contact strip (6), which is used to transfer all data be tween
the camera and the lens, including the control commands for autofocus, the diaphragm and, if
present, the central shutter .
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