You go to take a photo and everything looks as if it was shot through a steamed-up window. Wiping the lens does nothing, because the mist is on the inside of the glass. It looks alarming, but in most cases it clears without any harm done.
Why it happens
The air inside a phone always contains a little water vapour. When the camera's glass cover is colder than that air, the vapour condenses on it, just as a cold drink collects droplets on a warm day. Common triggers:
- Walking from an air-conditioned room or car into hot, humid air.
- Coming indoors from the cold in winter.
- Using the phone in a steamy bathroom or kitchen.
- Heavy monsoon humidity over several days.
- A recent splash or dunk that left moisture inside.
Phone makers acknowledge this. Samsung, for example, notes that condensation can form in the camera lens of water-resistant phones after sudden temperature changes and that it is not a fault.
How to clear it
- Move the phone to a dry room at normal temperature. An air-conditioned room is ideal, since air conditioning removes humidity.
- Take off the case. It traps moisture and slows the phone from reaching room temperature.
- Leave it alone for 30 minutes to a few hours. As the glass warms to match the air inside, the fog evaporates.
- Add airflow. A fan nearby speeds things up.
- For stubborn fog, seal the phone in a box or bag with several fresh silica gel sachets overnight.
What not to do
- No hair dryer or heater. Heat can damage the camera's tiny stabilisation mechanism and the adhesive around the lens.
- No direct sun. The lens focuses sunlight onto the sensor and the phone overheats.
- No fridge or freezer. This makes condensation worse when you take it out.
- Do not press or pry at the lens cover.
Harmless condensation or water inside?
| What you see | What it means |
|---|---|
| Even, light mist that fades within an hour or two | Normal condensation from a temperature change. |
| Fog that returns every time the phone warms up | Moisture is trapped inside. The seals may be worn. |
| Visible droplets or a water line behind the glass | Liquid has got in. Switch off and have it serviced. |
| Fog plus other symptoms: muffled speaker, charging alert, screen marks | Water ingress. Treat as water damage. |
If it looks like the last two, follow how to fix a water damaged phone and do not charge it.
Preventing it
- When moving between cold and hot places, keep the phone in a pocket or bag for a few minutes so it changes temperature gradually.
- Keep the phone out of the bathroom during hot showers. See phones and showers.
- In very humid weather, store the phone overnight in an air-conditioned room, or keep a silica gel sachet in your bag.
- If the phone has been repaired, ask whether the water-resistance seal was replaced. A missing seal lets humid air in freely.
Will fog damage the camera?
A single episode will not. Repeated or long-lasting moisture can leave spots on the inside of the glass or encourage fungus on the lens, which shows up as a permanent haze in photos. If fog keeps coming back, have the seals checked.