By preventing it, because once moisture is inside a lens it leaves slowly and nothing safe hurries it. Warm the equipment gradually in a closed bag rather than exposing cold glass to warm air.
Condensation forms when air meets a surface colder than its dew point. The camera is the cold surface, and the fix is to change its temperature slowly.
The prevention, which is the whole technique
Before going indoors, put the camera in its bag and close it. The bag holds the cold air that was already around the equipment, and both warm together over an hour or two. Nothing condenses because no warm humid air reaches the cold glass.
What not to do
Do not take a cold lens straight into a warm room, and do not hurry it with a heater or a hairdryer: uneven warming moves moisture around inside rather than removing it, and heat is its own risk to a cemented group.
If it has already happened
Leave it, sealed and at room temperature, until it clears — hours rather than minutes for internal fogging. A silica sachet in the bag helps a little and cannot be relied on.
Where this sits among the winter problems
Alongside the two others: cold reduces battery capacity well below any published shot count, and melted snow behaves like rain at the joints. The three are separate, and only condensation happens after you come in.
What people ask before they commit
Can I wipe it off?
The outside, yes, with a cloth intended for the purpose — and it will return while the glass is still colder than the air. The inside cannot be wiped at all, which is the whole reason prevention is the answer rather than a technique for removal.
Is a sealed body immune?
No, and sealing is a separate question in any case: **no title in this catalogue publishes an ingress protection code**, so the word describes an intent rather than a grade. Condensation is about temperature difference, not about water ingress — a well-sealed body brought from cold into a warm kitchen will still fog.
Last reviewed 12 September 2026