Yep - and humid air can enter the same way. If the lens then gets chilled it
can then condense inside.
LEE
----Original Message Follows----
From: "Brian Swale" <bj@xxxxxxxxxxxxxxx>
To: jochen.schiffler@xxxxxxxxxxx, olympus@xxxxxxxxxxxxxxx
Subject: [OM] ( OM ) Dust in lenses
Hi Jochen,
Lenses are not sealed airtight. There's no practical way they can be.
Every time a lens is focussed to a different focal length (except for IF
lenses), the lens body increases or decreases in length. This means the
lens volume alters. Thus air moves in or out of the internal cavity as the
air pressures inside and outside the lens equalise..
If the outside air is dusty, dust enters the lens then settles on any
surface to
which it is attracted.
And there's your answer.
Brian
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