Quick one this week – I think I mentioned someplace that I’ve been a little busy, and so too little time to prepare with images and so on. However, we’re just entering into the season for this in roughly half of the US, while the northernmost portions might see very little application of this advice, and the southernmost may have already been dealing with it. There are also times when it applies in entirely opposite conditions, too. So let’s deal with condensation.
Basic premise: If the humidity is anything above very dry and the temperature of your camera equipment, specifically the lenses, is significantly below the ambient air, condensation will form on the glass very quickly. Usually, this is from the equipment sitting within an air-conditioned house or car long enough to reach the same temperature, and then suddenly being exposed to the much-hotter summer outdoors. However, this can also happen when entering a hot and humid environment such as a rainforest or butterfly enclosure, or a greenhouse (or, actually, a busy kitchen.) But then, it can also happen in the winter, when the equipment has been outside enough to get significantly chilled, and then enters the average indoor temperatures. Having your lenses all foggy means you’re not going to get pics of much of anything until it clears, but worse, if this gets into the camera body itself, there’s a chance for both electronic trouble and actual damage, though such circumstances are rare.
The solution? Never expose your equipment to significant temperature differences. Though at times this is not only impossible, it completely ignores that we intend to be taking photographs at these temperatures. So, how to handle them?
Leave the lens cap on until the lens is well warmed up. This will take several minutes, as in, perhaps twenty or more. Do not take it off real quick ‘just to check’ – there’s no such thing as fast enough not to have the adverse effects. At times, if you’re in an environment with forced air (like a butterfly house,) you might be able to find the blower exhaust and leave the camera within the air flow to speed up the process, but the key is, the lens barrel does not feel even a little chilly when you handle it. Then it may be okay to check.
Take the equipment out of the bag. This is for going from air-conditioning to higher ambient temps. Camera bags are padded, which means insulated, and it can take an hour or better for the warmer air to bring the contents up to ambient.
By the way, I’ve tried warming the lens barrels in my hands, and it didn’t seem to significantly decrease the wait times, certainly not half as much as the suggestion below.
Use the sun. If you have direct sunlight, even through glass, place the camera and lens there to shorten the warmup time. This is the nice thing about them almost always being black – they absorb the heat from sunlight better. Monitor this, though – you never want your equipment in sunlight long enough to get hot, since this can also be damaging, especially by causing lubricant within the lens (for focus and zoom rings) to get thin and runny. Again, expensive repairs (or outright replacement.)
Do not switch lenses. Especially with another that’s been sitting in the bag, even after your primary one has warmed up. Condensation on the interior lens elements can take a very long time to clear, and stands the chance of leaving behind residue that is very hard (expensive) to clean.
Probably leave the battery (and film) doors closed too. Generally, the outside shell of the camera is resistant to ambient humidity, but not when any access doors are opened. The chances of getting so much humidity within that it damages anything is slim, but why take chances? A few minutes wasted is better than several hundred dollars worth of equipment or cleaning fees.
Ah, hell, we didn’t wait long enough. Or we didn’t expect the humidity to be high enough, or we simply forgot. Now the lens is all fogged up. Now what?
We still have to wait. It’s not going to remain clear, even if we wipe it away, until the temperatures have come closer to matching. Wiping isn’t recommended, for two reasons. First, this always takes the chance of scratching the lens with something coarse that we didn’t realize was present, and even if we use a blower of some kind to try and get rid of this, the moisture may be sufficient to keep it in place on the glass. Second, any cloths soft enough to use on lenses, like microfibers, aren’t terribly absorbent, and may push around as much moisture as they absorb.
Worse, they can also collect the moisture into droplets, and if there was anything other than pure water in the air, this takes the chance that residue gets left behind in spots, rather than carrying away as the lens dries naturally. Then we still have to clean the lens.
No, lens pens and the like do not work. They don’t absorb enough, so we’re only pushing the moisture around. Concentrated droplets take longer to evaporate than a light fog, so this may actually lengthen our wait times.
Blot, don’t wipe. If we have to try and clear things quickly, a very clean cotton cloth works better, because they absorb more. Just hold them against the glass and let them absorb, without wiping – it’s safest that way.
Fans again. Moving air is best for temperature exchange and evaporation – this is also best if our equipment got a little too damp from an unexpected rainstorm, or our bags got wet. Put them in the airflow and let them sit for a bit. The wetter, the longer.
Do not leave equipment in even damp bags – this is notorious for driving humidity deep into camera equipment. Take everything out and dry the bags thoroughly, at least overnight – the longer the better.
Can we save ourselves the hassle, and prepare ahead of time? Possibly, but probably not significantly. Leaving the loaded bags outside in a sheltered area, like on the screened porch or at least under an overhang and out of direct sunlight, for about an hour should bring the equipment up to the ambient temperatures. Leaving the A/C off in the car and having the windows open while we’re on the way can work. Not having the indoors A/C set as cold. But most times, we just have to be patient. And believe me, there have been plenty of times that I was rushing out to try and get some particular shot, to get nothing while I sat there fanning the lens madly to clear the condensation.
So, know the hazards, and what not to do at least. Good luck!