Weird glare visible at night.

[luk8899]

I have a number of the same type of noname cheap 2.7mm imx415 cameras. All but one are perfectly fine.

One, installed recently has a very weird issue. It has some sort of "glare" on one side of the image. It leeks like the ir illuminators is hitting some dirt/grease on the inside of the lens, but during the day the picture looks perfect. And, one can't see anything when looking at the camera.

I even considered it is another camera shining into it's lens, but no. Switching nearby cameras off makes no difference.

There is a piece of spiderweb towards the top of the picture. It just appeared today. It is not related to the blur towards the left edge. Here is a picture:

It looks like a dirty lens, right? But I assure you again, during the day it looks perfect and I can't see any dirt or grease from the outside.

Any ideas?

 

[wittaj]

You are seeing the "magic" of infrared and dirt on the lens or IR bounce. It doesn't take much for IR bounce to happen.

You could have something just off the field of view that IR is bouncing off of, it could be microscopic dust or dirt, or you have a rolled gasket letting IR bleed.

 

[bigredfish]

Is the camera a dome?

 

[EMPIRETECANDY]

lens cover dirty or have some vapor inside the lens.

 

[luk8899]

Is the camera a dome?

It isn't. It is this style(with antenna removed and sma connector terminated):

The case is metal and it is glued shut, except a small gasketed port at the bottom. Perhaps the seal there has rolled as was said.

The entire front is a transparent piece of plastic with a hole for the lens and on to that, a piece of IR transmissive plastic that appears black is glued. It is also possible there is something in the glue?

I'm not looking forward to having to take it off as the access is not easy.

But, if it is dirt it may well be internal and the camera might need to be replaced. I removed the protective foil as a very last thing after it was installed so I'm pretty sure I haven't touched it.

We often have spiders putting their nets right over the lens, but that looks quite different.

 

[wittaj]

I think the outside just needs a good cleaning.

 

[luk8899]

I think the outside just needs a good cleaning.

Sadly it didn't help. I finally got a huge ladder, got up there and I cleaned the front with iso alcohol. During daytime it looks great, but the glare is present at night. Also I had a good look at the lens. I can't see any condensation or anything else inside.

I think I'll have to send it back on the warranty.

 

[wittaj]

Have you moved the camera around to ensure it is not picking up reflection from anything?

We have seen soil that was metallic in nature bounce back weird reflections.

Or it is simply a cheap camera with a rolled gasket allowing IR bleed.

 

[EMPIRETECANDY]

Looks like the structure problem of the camera, that glar is from IR reflection.

 

[luk8899]

Have you moved the camera around to ensure it is not picking up reflection from anything?

We have seen soil that was metallic in nature bounce back weird reflections.

Or it is simply a cheap camera with a rolled gasket allowing IR bleed.

I haven't tried moving it. I tried swithing other nearby cameras off to make sure it is not getting any IR shine into it(there is another camera a meter higher on the same pole). I also tried pointing a PTZ camera into its field of view at night and I tried switching off its IR illumination, but that didn't work, because the camera has one setting that controls IR illumination and IR filter... When I disabled IR illumination it immediately enabled the filter...

Next time I'm up there I'll be replacing it with another one. I have 6 if I remember correctly of this exact model and only this one has this issue. I still have one spare left. There is a plastic box with a PoE adapter that's mounted beneath the camera. I'm also suspecting that perhaps it is reflective to IR? IDK. When I was setting up the next pole with very similar configuration I mounted that box behind, not below the camera. I hope to have an answer in few days.

 

[luk8899]

And the mystery is solved!!!

I replaced the red plastic diffuser (pictured below) taking one from another unit and the problem went with it. By this I mean the camera on the pole can see a great picture, while the new one that has the old diffuser now has this glare.

It looks like this
In the back it has molded clips that go into screw holes.

I'm very glad I don't have to be replacing the entire camera