Leica SummArIt-S 1:2.5/120mm ASPH. Notice D'utilisation page 16

Summary: The LEICA APO-MACRO-SUMMARIT-S 120 mm f/2.5 provides exceptional imaging
performance from the infinity setting to a scale of 1:2, at full stop and when stopped down.
Along with its very high speed, this means that it is the equally impressive as a (portrait) tele-
photo lens and for macro shots. In addition, this provides a free choice of aperture, including
full stop, for composition, with no need to worry about any deterioration 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 between
the camera and the lens, including the control commands for autofocus, the diaphragm and, if
present, the central shutter.
13