Being from the United Kingdom, I am well versed in protecting my camera against drizzle and Brexit, but the rainforest and high humidity were entirely new beasts.
I'm very familiar with how to handle my camera in extremely low temperatures, having shot in Iceland, Norway, and the Alps. But high humidity takes a lot more thought, preparation, and care to avoid rendering your camera unusable or worse, damaging it. Here are some tips for people going to high humidity locations for the first time that I picked up from local professionals, photography tour guides, and a few other reliable sources while I was in Costa Rica.
1. Acclimate Your Camera
The biggest difficulty for your camera in high humidity is not necessarily the temperature or the humidity, but rather the sharp shift in temperatures from air-conditioned cars and buildings to the outside. My first morning in jungle conditions was in Mexico, where I left my freezing cold room and stepped out into the morning heat, and my camera's sensor and the lens fogged up immediately. When I visited Costa Rica with Fujifilm, one of our guides that Fuji hired (Rob Knight Photography — brilliant tours of Costa Rica if you're interested) suggested that an hour or so before I went out for the day, I should put my camera bag out on the balcony and let it adjust.
2. Silica Gel Packs
If you've ever bought almost anything online, you'll have seen tiny white packets with "silica" or "desiccant" written on them. These are used at an industrial level for their water-absorbing properties, and they can keep moisture away from electronics or even keep food crisp. Buy (or save) a bunch of these — they're inexpensive — and keep some in your camera bag.
3. Keep a Lens Cloth With You
No matter what you do, you will have your lens fog up with moisture at some point. If you try to wipe it clean with your t-shirt or an ordinary cloth, your images will become cataract simulations. Get some proper microfiber lens cloths, and make sure you always have some with you. If it starts to get damp, switch it out, or you'll be quickly back to soft, overexposed images.
4. Dry Your Equipment
It isn't just the optical elements of your equipment that require your attention. Leaving your camera moist from the environment or whatever sources you may encounter could creep into your camera and cause problems. Periodically dry your camera body and lens with an absorbent towel. One crucial addition to this: if you go near the sea and your camera gets splashed, even if it's weather-sealed, you must wipe it with a cleaning cloth to get the salt off, and then dry it. Salt water can be the devil.
5. Avoid Changing Lenses
I was told this one by several different people. I'll be honest: I rarely adhere to this rule, but the inside of your camera is usually a lower temperature than the outside, which is exposed to the sun. So, taking the lens off can cause moisture and condensation on the sensor, which is bad news. However, it seems that if you change lenses enough, the inside doesn't cool down enough for it to be a problem. Similarly, zoom lenses were pushing warm air into the inside of the camera anyway. Your safest bet is to not change lenses unless you really have to, though, as it does increase the chance of moisture getting inside.
Summary and Your Best Tips
There are other ways to combat the spikes and plummets in temperature and humidity in tropical locations. If you're in one long-term, there is of course also the option of purchasing a dehumidifier to keep an area of where you're staying nice and dry. A lot of people also use Ziploc bags, but that didn't make a great deal of difference to me.
Do you have experience photographing in high humidity? What advice can you give first-time travelers to these locations for protecting their gear from moisture and fogging? Share them in the comment section below.