Humidity, Fungus & Cameras. How to care for your camera equipment in high humidity conditions

Humidity, Fungus and Cameras – Problems & Solutions

Camera equipment is sensitive to moisture, and dust. I’m going to deal with a couple of ways in which you can keep your equipment safe from high levels of humidity that could damage your lenses and certain parts of your camera body. We will deal with dust in a subsequent post.

Fungus grows in between lens elements and under the lens coatings. Once it starts growing, it is difficult to get rid of, and causes soft spots in your photographs. It is like having a fingerprint smudge on your lens. This is one case in which the prevention keeps the lens doctors away.

Why High Humidity is Bad for Your Equipment

Fungus or Mould thrive in dark, humid places where there is little, or no movement of air (sound familiar? look at where you store your camera equipment). Very often camera equipment ends up in drawers, cupboards, or basements; all of which are dubious places to store them. Remember that keeping your camera in storage for too long is also a recipe for fungal (and mechanical) disaster. Lenses and cameras need to be kept in use and exposed to light and fresh air from time to time. A camera or lens that is used well, and stored correctly is most likely to see many years of successful picture-taking.

Ideal Camera Storage Humidity Range

Lenses and camera equipment are optimally stored at a relative humidity (RH) of around 35% to 45%. A good rule of thumb to figure the optimal RH to store your equipment at, is to look at it’s optimal operating humidity range, and make it half. For example, the Canon EOS 5D’s operating humidity range is 85% RH or lower, so a good indicative range to store it would be between 35 and 45% RH.

Humidity Range – Why Very Low Humidity is Bad for Cameras

Remember that you could also run into problems from keeping your RH levels too low. All camera lenses and bodies have a number of moving parts – gears, sliding thingies, and rolling thingies – and they’re all lubricated with a light machine oil. Keeping your RH too low could dry up that oil quicker than usual, making these parts wear out sooner, and work sluggishly. I also think that the rubber on the camera tends to harden quicker in dry air.

There also seems to be another kind of mould that affects camera equipment at very low RH levels; I’ve only come across this in one place, so I don’t have much info on that. If you have some information that you could add, please do leave it in the comments.

High Humidity can be bad for camerasPhoto: dawn_perry

Solutions that Reduce Humidity

So what’s the solution? The cheapest option is to use your camera as frequently as possible; The exposure to light, especially UV light kills the fungus. While this is not a problem for active enthusiasts, those who store their cameras for any length of time need an alternative.

Option 1 – Sunlight / UV Radiation

Put your camera out in the sun from time to time. Remove the lens (or you could end up with a hole burnt in your shutter or some other part), filter, body, etc, and put them all out in sunlight for a while. If you manage to work this into your monthly camera care routine, you should be fine.

You could also try what some photographers do: use a High Power UV lamp in their storage area. Why? Because prolonged exposure to UV (Ultra-Violet) radiation kills or retards fungal growth. Do remember to take your UV filters off if you decide to try this method out, because they are designed to keep UV rays out of your lenses. The lens coating blocks UV light too, to an extent.

Ok, so you’re exposing it to light on a regular basis, but what if you live in a region that is perpetually humid? See alternative 2 for an answer.

Option 2 – Desiccants

As always, there are the cheap options and the expensive options. In either case, you’ll most likely need a Hygrometer so that you know what the relative humidity is at any given time.

1. Cheap Option – Silica Gel

Silica-Gel is the cheap way out. It is a desiccant (something that dehumidifies the air in the vicinity of your camera equipment).

You can buy Silica Gel either as crystals, or sometimes as tiny spheres. Most often you find them in porous sachets so that they don’t disperse among your equipment. If you decide to go with Silica Gel for your cabinet, remember that you should get the indicative variety. The crystals of Silica gel are blue coloured when they’re fully absorbent, white-ish when they’re partially full of moisture, and pink when they’re fully saturated with moisture and can not absorb any more. You can Recharge your Silica Gel at this point. In fact, keeping the silica gel in the camera storage beyond this point can see some of the moisture escaping back into the atmosphere.

You’ll need a container like the Dry Storage Silica Gel Dehumidifier to store it, yet create enough airflow through the crystals. You’ll also generally need lots of silica gel. But remember that it lasts a long time, and needs no further investment.

Again, remember that keeping saturated silica gel in your camera storage could do you more harm than good by actually releasing more moisture into your storage.

2. Expensive Option – DeHumidifiers

As with everything, there has always got to be an expensive option. De-Humidifiers usually use mechanical means to reduce the relative humidity of the air around it. De-Humidifiers are usually quite effective, and can reduce the time you spend on modifying your camera’s environment, but they generally draw significant amounts of electricity.

You could also use your Air Conditioner to reduce the ambient humidity to a safe level for your camera equipment. This is because Air Conditioners dehumidify as they chill the air, leaving a comfortable storage humidity for lenses and cameras.


To wrap up, remember that the best maintenance / fungus prevention plan for your camera involves your regular use of the equipment. Regular use keeps the lenses and camera body aerated and exposed to sunlight, thus killing any fungus.

If you don’t use your camera often, make sure that it is stored in a well-ventilated area with an ambient humidity range of 35%-45% RH. Also, remember to take it out often and expose it to sunlight.

If you live in a humid part of the world, you could try one of the other two options mentioned above – Chemical Desiccants or De-Humidifiers.

If you have had experience with fungus and humidity affecting your camera equipment and have found an alternate solution to those mentioned above, please do leave a comment so that our readers may benefit from your experience.

EDIT: I recently came across these two very interesting items on I’m going to be investigating their potential use in photo equipment storage, but here you go anyway.

Featured Photo: ~jjjohn~