I'm having internal lens fog issues with my brand new Action 2. My main use of the camera is on the FPV drone and after each flight I'm having the lens being fogged up pretty bad, regardless of what resolution I'm recording on.
My guess is that there is some humidity trapped inside the camera (probably during manufacturing process or storage) and when the camera heats up slightly after being turned on and set up before recording and then cooled down quickly by the air blowing around it on the drone, the sudden temperature and pressure change makes the humidity to appear inside the lens itself or under the front covering glass.

This is already second unit with the similar issue that came in my hands (I bought the previous one as used and promptly returned it because this issue) and it happens literally every time I use it on my drone. I discussed it with multiple Action 2 owners who use it for the same purpose as I do, but nobody except one ever had any similar issue so I refuse to believe it's the normal behavior (especially when the mail camera module is advertised to be water resistant).

In case anybody asks:

• the camera unit is brand new (straight out of the box, activated, purchased care refresh and did the test flight)
• the camera didn't experience any submerge in the fresh or salt water whatsoever
• the test flight was performed in 15 degrees Celsius and 55% of air humidity (so not very humid or cold environment)
• test was performed while recording on 4K resolution at 30 frames per second and on 2.7K at 60 frames per second - both resulting in fogging up the lens.
  

Right now I have the camera stored in the sealed container filled with silica gen beads hoping it would capture any humidity through the air pressure hole or microphone hole.

Is there any advice about this? Did anybody have the same issue?

Thanks in advance.

We apologize for any inconvenience caused by this issue. As the sound recording module is wrapped with a waterproof and gas-permeable membrane, which does not completely isolate air. Therefore, when the device enters a low temperature environment from a high temperature and high humidity environment, water vapors may condense on the camera glass, which will gradually dissipate after left idle for a period of time.

DJI Mindy Posted at 3-15 06:38
We apologize for any inconvenience caused by this issue. As the sound recording module is wrapped with a waterproof and gas-permeable membrane, which does not completely isolate air. Therefore, when the device enters a low temperature environment from a high temperature and high humidity environment, water vapors may condense on the camera glass, which will gradually dissipate after left idle for a period of time.

Thanks for the reply. What you're saying actually makes sense and might be the reason of the issue. For testing purposes, I covered the mic hole on the camera face and tried it again. This time no condensation appeared regardless of what recording resolution I selected. It still needs more testing but I believe it will be better now. I don't really care for sound recording on FPV drone so covering the mic is not a problem for me.

put it in a small lock lock box with dry silica and turn the camera on, or use the dive cage with
dry sheet

Waterproof is not water vapor tight

cjr888 Posted at 3-15 08:13
Thanks for the reply. What you're saying actually makes sense and might be the reason of the issue. For testing purposes, I covered the mic hole on the camera face and tried it again. This time no condensation appeared regardless of what recording resolution I selected. It still needs more testing but I believe it will be better now. I don't really care for sound recording on FPV drone so covering the mic is not a problem for me.

You're welcome. Glad to know this helps. If you have any further inquiries, please feel free to contact us.