Cottage Tip: Keeping Humidity under Control- Part 1

Humidity is one the worst enemies of your cameras and lenses! We all know that under prolonged humid conditions, especially if stored in the dark, fungal growth can begin inside your beloved lenses! The best cure is, of course, keeping your equiment in constant use (fungal growth is quite sensitive to light). But most of the time, our beloved toys reside in a bag or a case, in the dark. Unless you live in an arid environment, we need to make sure there is not enough moisture inside to initiate the growth of the evil fungi! Fortunately, fungal growth is quite a slow process, and won't happen overnight! Many photographers just put (intuitively) inside a bag or two of silicagel they recycled from a shoe box or other purchased goods. The problem is, this silicagel is probably already exhausted, so it has no capacity left to absorb the moisture. Plus, it usually has no color indication whether is exhausted or not. Most of the people just put inside these little bags and forget about them for good! Fourtunately, most people don't have problems with fungi, but some of them do, sadly. 

This is all you need: fresh silicagel, a film canister and a sharp tool (e.g. scissors). Rightmost: a bag of exhausted silicagel.

This is how a punched canister looks like.

Left: film canister with fresh silicagel. Right: canister with exhausted silicagel, notice the color change.

 The real solution to the problem is to buy silicagel beads with color indicator in bulk-you can buy half a kilo or so for little money online. As the silicagel gets too wet, it turns its color from orange to dark blue (it looks like caviar-before and after-salmon before, beluga caviar after J). So, buy silicagel in bulk, and you can regenerate it many times by (re)heating it! Next problem is the container; I simply use a (translucent) film canister, finely punched along its surface. Pour the dry silicagel inside and close the lid. A canister or two will do their job for a few weeks or months inside the bag (or case), but not forever! Moisture penetrates more than you can imagine inside your bags and cases (unless you have everything sealed with plastics-not really practical), so a regular check is advisable. When it comes to regenerate, simply put the silicagel in a shallow (glass or metal) container or pan inside the kitchen oven for an hour or so around 100 °C. When it turns back orange in color, you're done! When not in use, keep your silicagel well sealed against moisture. The humidity in your closet or drawer, where you keep your gear, is also important. We'll cover this in the second part.

A note of caution: with time, some fine dust will occur, due to silicagel's self-abrasion. Do not breathe the dust, it's not friendly to your lungs!

Mitja