Hi everyone,

I just became aware that I'm not the only one with this problem. Bought my drone about a month ago in The Netherlands, and currently residing in Indonesia.
When flying my drone, within a minute or so, the lens fogs up, on the inside, and stays that way until landing and waiting for a few minutes.
I've been doing some experiments:

* Room and outside temperature and humidity here are practically the same (25 degrees celcius, ~80% humidity). Still I tested the drone flying inside, hovering at 1.5m, and the lens fogged up within a few minutes.
* Someone pointed out that the lens only fogs up with the props spinning. This is indeed the same case for me (no fog when just using the camera and the legs folded).
* Except when I point a room fan at the lens. In this case the exact same thing happens (fogged up within a few minutes).

It's clear to me that this is a product defect. There's moisture within the camera module, and cold air either from movement or the props cools down the lens and triggers condensation within the module.

I'm not sure how I can return the drone as I'm pretty far away from where I bought it. I have contacted DJI support about the issue and hope they will help me out in solving this.

Hi there. Thank you for reaching out and we're deeply sorry for the trouble that this has caused. We're glad that you have already managed to contact our team with regards to the said issue. Kindly please wait for their updates as there might be an existing case of yours on our end. Should you have other inquiries, please don't hesitate to reach us. Thank you for your understanding and support.

I have the same fogging issue.

It seems like this is far more widespread than originally thought.

I’ve raised a case to send mine in for repair but I’ve seen other threads were people have received a few replacements and still had the same issues, so I’m now hesitant to send mine off.

Not great for brand new drones which aren’t cheap.

I think the reason is high humidity in the air (mainly in hot countries with rain forests) - this humidity changes into fog at surfaces with a high temperature difference. Inside camera hot - outside of the camera cooler. However whatever causes the issue doesnt mater its a product failure - usually for this reason products are tested in a climate chamber.
It can even create fungus on the optics in the long term.

a similar situation.  the camera fogs up after the flight and passes over time.  I don't have much +25.  Yesterday it was +12, today +10.

DJI Paladin Posted at 6-26 04:02
Hi there. Thank you for reaching out and we're deeply sorry for the trouble that this has caused. We're glad that you have already managed to contact our team with regards to the said issue. Kindly please wait for their updates as there might be an existing case of yours on our end. Should you have other inquiries, please don't hesitate to reach us. Thank you for your understanding and support.

Thanks DJI Paladin, I’ll be awaiting their reply

De Fender Posted at 6-26 09:07
I think the reason is high humidity in the air (mainly in hot countries with rain forests) - this humidity changes into fog at surfaces with a high temperature difference. Inside camera hot - outside of the camera cooler. However whatever causes the issue doesnt mater its a product failure - usually for this reason products are tested in a climate chamber.
It can even create fungus on the optics in the long term.

I agree De Fender, I also think it has to do with high humidity. During my flights in The Netherlands I had no issues. Here in Indonesia it’s simply unusable. This might also indicate that the moisture came in here in Indonesia, otherwise it would’ve fogged up before as well. This probably means it’s not sealed properly.

I've done some more testing to get a better insight in the problem.

The drone is not in flight.

This 5 minute timelapse shows that the airflow from the fan hitting the lens causes the condensation:



I did the exact same test without the fan resulting in a correct recording:

I've not had this experience with my Mini3Pro, so it does seem that yours may be defective. Bad luck!  I sense your frustration. Hope DJI solve it for you amicably.

Where precisely is the condensation i.e. on the inner/outer face of the removable front lens/'filter' or on one of the proper lenses in the camera-proper?
Especially if the fogging is on a "proper lens", when the drone is switched on does the camera's body shell get warm/hot?
I have seen one solution that supposedly worked but can't remember where I saw it, the poster drilled a hole in the camera body.
I AM NOT suggesting that anyone does that, in fact I would suggest it is NOT DONE as it would almost certainly invalidate warranty etc. and a slip could result in the drill bit destroying the camera's innards, but it does raise some question as to where the moisture is 'trapped'.

If you put a strip of tape across the gap between the front sensor (to prevent prop wash flowing over the camera) do you still get condensation forming?

If the drone is stored for some time in a sealed plastic bag containing a deliquescent e.g. silica gel, NOT rice, do you get condensation on a subsequent flight? (with or without the above tape)

Good videos and tests clearly showing the issue.

I've just posted mine off today to DJI Australia for the same issue.  Hopefully it's fully resolved when it returns.

I had this once,  I landed wiped the lens and was good to go,   I wonder if a UV filter on the camera would help at all.

Sean-bumble-bee Posted at 6-27 00:35
Where precisely is the condensation i.e. on the inner/outer face of the removable front lens/'filter' or on one of the proper lenses in the camera-proper?
Especially if the fogging is on a "proper lens", when the drone is switched on does the camera's body shell get warm/hot?
I have seen one solution that supposedly worked but can't remember where I saw it, the poster drilled a hole in the camera body.

Thanks for the suggestions Sean!
The removable filter doesn't have glass, the condensation is on the inner face of the actual camera module. As this is a sealed compartment no moisture should be in there, but for some reason it is.

Having no airflow directly on the lens does prevent the condensation. Haven't tested with tape though.

I did put the drone in a container with silica gel but the problem persists. I'll have another go and leave it a bit longer.

My theory is that the heating and cooling down of the camera module creates pressure differences, which combined with a bad seal allows air in and out. If this indeed only happens under pressure, it would be very difficult to get this moist out...

DAFlys Posted at 6-27 02:59
I had this once,  I landed wiped the lens and was good to go,   I wonder if a UV filter on the camera would help at all.

The condensation is on the inside of the lens, so cannot be wiped off
The UV filter would be an interesting test!

Monkey Station Posted at 6-27 22:32
The condensation is on the inside of the lens, so cannot be wiped off
The UV filter would be an interesting test!

When mine fogged up it was on the outside.  I landed and wiped and all was fine after that.

Monkey Station Posted at 6-27 22:30
.......The removable filter doesn't have glass, the c..........

oooooo  I don't like the sound of no glass in the 'filter' at all, there's no protection from flying grit for the real optics.

Monkey Station Posted at 6-26 14:22
Thanks DJI Paladin, I’ll be awaiting their reply

You're welcome. Again, we're deeply sorry for the inconvenience. Have a good one!

Sean-bumble-bee Posted at 6-28 06:13
oooooo  I don't like the sound of no glass in the 'filter' at all, there's no protection from flying grit for the real optics.

It's really not a big deal. Using a lens pen should always be implemented anyhow. The Freewell UV lens does provide great protection as well.

KLRSKIR Posted at 6-29 05:56
It's really not a big deal. Using a lens pen should always be implemented anyhow. The Freewell UV lens does provide great protection as well.

I wasn't thinking of cleaning or ease of cleaning, I was thinking of scratches on the real lenses, a filter would hopefully prevent them.

Sean-bumble-bee Posted at 6-29 08:19
I wasn't thinking of cleaning or ease of cleaning, I was thinking of scratches on the real lenses, a filter would hopefully prevent them.

Yeppers, absolutely would. Never in my years of flying drones have I "had" to take-off nor land in poor dusty/dirty conditions. I've only had the occasional "bug-schmeg" buildup on the airframe and camera, and once a tree with the FPV.

It may not be necessary to take off and land in dusty conditions but people do.

It seems one consumer in china found the root cause of lens fogging.

It should be the camera o-ring assembly issue.  

https://www.bilibili.com/video/BV1Pv4y1w7ai/

endless0925 Posted at 6-29 18:05
It seems one consumer in china found the root cause of lens fogging.

It should be the camera o-ring assembly issue.  

Thanks for sharing! As DJI doesn't offer global warranty and I'd have to send my unit back to the Netherlands from Indonesia, I've decided to take a look for myself.

Indeed the seal is crooked:


Sadly it's not just a simple o-ring, but more of a rubber housing. And it doesn't want to be pushed back in my case.


I've tried as best as I could and put it back together, but sadly that didn't fix the problem. Which makes sense I guess, as it should be sealed in a dry environment.

To be continued I'm sure

De Fender Posted at 6-26 09:07
I think the reason is high humidity in the air (mainly in hot countries with rain forests) - this humidity changes into fog at surfaces with a high temperature difference. Inside camera hot - outside of the camera cooler. However whatever causes the issue doesnt mater its a product failure - usually for this reason products are tested in a climate chamber.
It can even create fungus on the optics in the long term.

I disagree, because in my Mini2 i haven't experienced the same issue at all.. flying the same location

My mini 3 has apparently been repaired by DJI today for this issue and is on the way back to me.

I’ll be interested to see if it is actually resolved or not. Hoping I don’t have to go through the return process again.