Invariably, someone has to jump in with their Leica and I wanted to know how it felt. In all honesty, I don't own a Leica. All of the lenses that I use on a regular basis are in my closet with no air vent stored laying down in a bambo/fabric shoe caddy that hangs from the clothes rack. Those that are specialty lenses get stored laying down in an engineers case on an inside wall away from any vents. I treat my equipment as I treat my guitars and that is to keep them away from high humidity and wild swings in temperature. Not always possible when shooting in the winter.