I spent a good amount of my time living in coastal cities with my photography equipment. Coastal cities have high humidity and this leads to a common problem in optics – lens fungus.
In the earlier days of photography, people were not much bothered about the fungus. People owned and used a single lens most of the time which helped by exposing the optical elements to sun-light every once in a while. This prevented fungus. Even if the fungus grew, people did not notice it till it started causing excessive softening of the pictures.
New lenses and a lot of other photography equipment (and a whole lot of other consumer goods) for whatever reason started providing few grams of silica gel in small packets, which was generally thrown into the packaging.
(Silica Gel beads commonly found when one opens a new box of goods)
This silica gel added more to the woes of the photographers. It gave a false sense of security and people started storing their new lenses for long periods with a couple of such small packets. More and more fungus attacks! A lot of people still do so. Let me first clarify on these silica gel beads. If you are using these, stop! Silica Gel has a limit to how much of moisture it can absorb and most probably the one that comes with new purchases is already saturated.
If you still want to use Silica Gel for storing your expensive glass, head to the nearest scientific supplies store. Ask for ‘Self-Indicating Silica Gel crystals’ and buy at least half a kilo of it. Next buy a desiccator or an air-tight large box. The crystals when dry are usually blue/purple in color and they turn white/transparent when they are saturated with moisture. Keep at least a fist full of these in the desiccator tray or a cloth bag along with the photography equipment and close the lid. Over the next day or two, the Silica Gel will absorb the moisture and keep the equipment dry. The Silica Gel will loose its color while it does its work. When it is time to replace the Silica Gel, it can be easily made dry again (dehydrated) by heating in a dry pan. Just make sure not to inhale the steam that rises out of it.
Based on desiccator, some companies came out with Dry Cabinets that used a chemical agent like Silica Gel crystals. These are basically glorified desiccators made to look like a small almirah or cabinet. They are better than conventional desiccators due to ease of use.
Few decades have passed and new innovations are making way into every nook and corner. One such useful product that has recently come to my home is an electrical Dry Cabinet. The one I have is by Benro. It is very well made and has a glass door on the front. There are trays to hold the equipment. The sides have white LED lights and a display on the top right which works as a hygrometer and also as a control panel to set the desired humidity level. It runs using an Nokia kind of power adapter. The Dry Cabinet works on Peltier Effect.
(Benro Dry Cabinet)
Advantages that I see with this cabinet are many. I can now store all my lenses and cameras in a single dedicated cabinet. The front door gives me easy access to everything and the light is quite useful. I no longer have to keep an eye on the color of Silica Gel or heat it every now and then. It is indeed a very useful product and keeps my mind at ease. It also provides better protection from dust than any other cupboard in my house.
Every rainy season, I thank the dry cabinet for keeping my unused lenses safe.
The best habit to prevent fungus is still the age old method – keep using the lens. Nothing better than sunlight to keep the optical elements safe.