Is camera at risk of condensation in cold temperatures if never removed from bag?

Question

My camera lives in my backpack, which I take with me almost everywhere.

The temperature where I live has dropped below freezing and will likely stay down there for the next 3-4 months. I've read the advice about wrapping your camera in an airtight plastic bag while outside, then allowing it time to acclimatize to warmer inside temperatures to avoid condensation inside of the body or lens.

My question is - does this airtight bag need to be applied while outside? Will my camera be okay if it is simply left in the airtight bag inside my backpack and carted in and out of the cold, with greater precautions taken when I am actually shooting with it outside? Are there any other steps I should be taking to minimize risk?

Answer 1

Personally, I have never taken any steps to protect the camera from condensation, and I've had the same camera for about 7-8 years without any signs of damage (although it is a 7D which is a pretty solidly build camera). The only precaution is that I don't change lenses immediately after I get inside.

Also, just leaving the camera in the bag will provide some form of protection. Although not as efficient as a sealed plastic bag, it could be sufficient.

Condensation happens when you bring a cold object to a hot environment. People wearing glasses notice this whenever they get inside from the cold.

The reason is that hot air allows for higher humidity, i.e. it can contain more water molecules (steam) than cold air. So when the temperature suddenly drops around the cold object, the water molecules form water droplets (vapor) which will condensate on the object.

So the ideal time to wrap up the camera is when you are done shooting for the day (remember to take the memory card out first, if you want to process images as soon as you get inside).

Putting the camera in a plastic bag while inside produces the opposite effect. You are capturing air with high humidity inside the bag, and when you bring it outside, and the temperature drops, the water will condensate inside the bag.

I think it's a bad idea to leave the camera in a plastic bag at all times, as any condensation that has been trapped inside the bag will not get out.

Answer 2

The whole point of wrapping the camera outside is to enclose it with dry winter air where the humidity has already been frozen out. If you wrap the camera while inside, you enclose it with humid air, then go into an environment where the air will not hold water, making the water condensate and/or sublimate inside of the bag.

Which is bad. The wrapping outside also means that the camera can warm up inside without getting exposed to warm humid air which would have water condense on the cold camera parts.

A way to improve the humidity transfer out is to drop silica gel bags in the plastic bag as well and regularly dry those bags in an oven (otherwise they end up giving out as much humidity as they collect). Those are long-term regulators and thus cannot save a cold camera from condensing water out of warm air. But at least they can shift an otherwise neutral balance in your favor if you regularly dry them by heating.

Answer 3

The coldest that I've had my camera in was a particularly windy glacier in Iceland. Very, very cold with the wind-chill (maybe -15 to -20 F). Went from that to a slightly warmer bus to a much warmer hotel. Didn't take any precautions - also didn't notice any condensation nor fogging.

What I've come to learn is that cameras are pretty darn tough and resilient.

Second example: My wedding photographer shot our wedding in Portland, Oregon, in March while there was snow on the ground (and indeed, more snow falling!). He went from out in that and back to inside shots without worry and I didn't notice any condensation or fogging on his equipment. Resulting shots didn't appear to be shot through a fogged lens either.

I'd love to see a study of what humidity levels and temperatures are needed to really cause problems for shooters...but until then, you've got just a few options:

Option A: Wait for the problem to present itself. Simply go about your normal shooting and, if you notice condensation or fogging problems, then look to solve.

Option B: Solve the problem before it occurs. Obviously, the absolute best thing would be to have an airtight bag with silica gel inside that you wrap your camera in while in cold areas and before bringing into warm. Outside of that, having some silica in your backpack and simply leaving it closed until things warmed up may not be too bad. But, if you need to shoot immediately inside...all bets are off, start shooting and prepare to wipe fog off the front lens element and pray it doesn't fog up inside the lens ;-).

All that being said, in my own experience...condensation issues are like the uv filter vs lens hood issues...everyone's got a reason to go one way or the other, and hardly any of us end up breaking the camera/lens anyway.