Leica SUMMARIT-S 1:2.5/35mm ASPH Instructions Manual page 19

Care tips for your lens
Dust on the outer lenses should be removed with a soft hair brush or carefully using a clean,
dry, soft cloth. Micro fiber cloths (available from specialist retailers) are ideal and can be
washed at up to 40 °C. To remove marks or fingerprints, wipe the lens with this cloth starting
in the middle and working towards the edge in a circular motion . Special cleaning cloths for
glasses should not be used as they are impregnated with chemicals that can damage the
types of glass and coatings used . Do not exert heavy pressure when wiping highly soiled lens
surfaces . Although the coating is highly abrasion resistant, it can be damaged by sand or salt
crystals . Never use acetone for cleaning .
The bayonet is given an ultra-thin film of grease in the factory to ensure that the lens can be
changed easily, gently and smoothly . In normal use, this is retained for many years even if the
bayonet is occasionally wiped with a clean cloth . If a substance that dis solves grease is used
for cleaning, the grease film must subsequently be replaced. To do this, coat the bayonet with
a tiny amount of Vaseline with a finger and spread using a clean cloth.
In addition to the type designation, every lens has its "personal" serial number . Note this
number in your documentation for security .
Dust and splashed water protection
Leica S lenses have a range of design fea tures that provide a certain amount of protection
against moisture and dust . However, they should not be continuously exposed to rain . Ensure
that neither water nor sand and dust can get into the lenses, e . g . when it is snowing or rain-
ing and on the beach .
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