Condensation inside lens

fronko wrote:

Amadeus21 wrote:

As I already said: Store the lens outside in the coldness. (I think there is enough at the moment in U.S. : (

Cold air is *very* dry. So you may make the lens "breath" in and out but agitating the zoom and focus function every once in a while for some days ( I think not below - 15 deg. C.) during a drying cycle.

No lens is air tight. So I think the owner before has done somerhing inappropriate with the lens. Furthermore and worse, there might be moisture in a *group* of lenses, which are cemented together in the factory. Then you will have to send the whole lens to Sigma definitely. You can have a look at the specs and construction of that objective (how many lenses in how many groups) at the Sigma site. Then you may see whether the frontmost lens is part of a (cemented?) group.

So my opinion.

Best wishes

Johannes

store it outside where? the lens is the 20mm 1.4 art dg hsm.

this one

https://www.sigma-global.com/en/lenses/a015_20_14/

Don't store any electronic or optical equipment outside the house, and also don't store it inside the house in cold conditions. If you do that's really the best way to grow mold on your lens.

Instead, keep it inside the house in a well-heated room. Probably the best place to store a camera is in fact in an office space or a living room. Bed rooms etc are not good because they are colder and there is a lot of moisture. Same for cellars and other nonheated storage rooms.

In the UK the housing stock is quite old and comparatively poorly insulated often with simple single glasing windows etc. So one needs to pick suitable rooms carefully, esp. for storing delicate equipment. For example don't store it in a room where there is window condensation in the morning.