Lens Fog #123

Lens Fog #123

Unless you're shooting in very dry climates like a desert, at some point you're likely to run into lens fog, whether it's cold out or hot out. Lens fog happens when there's humidity outside and you go from a warm place to a cold place or a cold place to a warm place. Imagine being in an air-conditioned hotel room and walking out into the humid climate of the East Coast in the middle of the summer. Yup, you're gonna have some problems. Or imagine going from a warm hotel room into a snowy winter's day.

The reason I keep mentioning hotel rooms is because I've come to find that people tend to keep their hotel rooms a lot warmer or a lot colder than they would their own homes because they're not paying for the energy bill. And because they have a super chilled or a super heated hotel room overnight, their equipment has had about 8 or 10 hours to acclimate to that temperature and humidity level. So when they walk out onto the street with their equipment, boom, fog everywhere. So what can you do?

Here are my strategies: first of all, when you get back to your room, take your SD card out and seal your equipment in your camera bag. This will make it harder for your equipment to come to the same temperature as the room. Then when you wake up the next morning and head to breakfast, take the bag with you and open it up in the dining hall. This space is usually a few degrees closer to the outside temperature than your room is. Then when you go outside, keep the bag open to the environment this will help it get to the temperature much faster. I know this may not be an ideal way to work, but it's a reasonable strategy. Along with this, I also put those silica pouches, you know, the ones that you find in shoeboxes? I put those in my bag as well. I would suggest that you do not use the ones that contain powder inside because if it breaks in your bag, well, you know what's going to happen. Ask me how I know.

If you still have fog because you couldn't do any of these things, or because you had to go directly from your hotel room to the shoot, the best way to get rid of it is not to use a cleaning cloth or a wipe, but a blower. Yep, a blower. It's something I learned from a birder in Costa Rica. He was doing this with his binoculars. Why a blower and not a wipe? Because the blower is blowing air that is the same temperature as the outdoor temperature, and what you're trying to do is you're trying to get your gear to that temperature. Trust me when I say it works way better than a wipe in this situation.

Also, you need to be careful to notice if there's humidity inside your lens or on your rear element. If it's the rear element, it's likely on your sensor too, in which case you really just need to wait until your gear comes to temperature. If you're attempting to clean a foggy sensor in the field, you will just smudge it more. Again, a blower would help to solve this problem much quicker as it's not only drying your lens, but it is also bringing the equipment to temperature. Although if the fog is in the center lens elements, you're really screwed. Just get a coffee and wait. That's it for today's podcast. I hope that was helpful.