Condensation inside lens

Amadeus21 wrote:

Hello Tom,

I dedicated *a whole paragraph* to moisture INSIDE a lens in my posting. And the danger of getting fungus inside the lens.

At my experience it nearly about NULL to get fogging *inside* a lens - except there is really a lot of moisture inside. Moisture is very rare within lenses - unless it has been caused by very inept use beforehand...

In order to get the moisture out of a lens, You may use silica gel-desiccant from all the Covid-19 tests, because there is always a little bag in it! One has to put the lens into a really tight box or a small plastic bag together with the silica gel.

I agree that sometimes lenses last great without accumulating moisture inside them.  I store my lenses under my bed in a large plastic box that is unsealed.  I don't run a humidifier in there at any time.  These lenses live like I do.  They like it just fine.

A few years ago, a friend wanted me to sell some older Leica equipment belonging to her deceased father.  I looked at it, and a year later agreed to help her with this.

What I did not know was that she had moved the equipment to the crawl space under the house for that year.  The house is in a place where humidity is high in the mornings, so humidity in that crawl space was much higher than it was in the upper floors.

The effects to the lenses were severe.  It was very unfortunate.

About plastic bags: if you put some crisp saltine crackers inside a plastic bag, and a week later the crackers are stale, the bag is letting moisture permeate through it.  So it is probably better to use a really tight box if you have any doubts.  Silica gel from any source is great, I agree.  But it holds only a certain amount of moisture and has to be carefully heated to expel this accumulated moisture.  So it is easy to end up using silica gel bags that are already saturated because they are packaged for single-use and generally do not have indicator features.