Flickering noise at nighttime on Dahua HDBW4231F-AS

[robo65536ru]

Hello. Can anyone tell me what is problem with this camera? IR lights turned off all time by settings in camera interface.
At night time appears flickering noise, like a image sensor defect?

 

[wittaj]

That almost looks like the electrical interference we would see with analog cameras of the cables going over electrical wires, but it is rare to see that with IP cams.

I wonder if the amount of light you have is struggling with whether it should be in color or not. What if you force it to B/W with infrared, does it stop?

 

[robo65536ru]

Forced B/W with IR light.

 

[wittaj]

Yeah that looks like some weird sensor issue with the snow and the roof right there and I think it is just having trouble trying to decide if it should be in color or B/W since it went away with the B/W and infrared.

 

[robo65536ru]

Forced B/W without IR LEDs.
This camera worked fine about 3 years on this place. But about two weeks ago flickering noise was appear. May be problem with power supply? Not working properly PoE converter 48V to 12V inside of camera?

 

[wittaj]

It could be a failing power supply, but it looks like the little pulsating is due to the iframes (which is common and can happen in certain situations).

The "interference" that look like analog electrical interference goes away when it is in B/W, so that is leading me to think it is either the sensor is getting confused with the lighting conditions (is it always snow covered there or did that just happen as snow can cause some crazy things with it being more reflective).

Are you running a backlight like WDR or SSA or something? If so try turning it off.

 

[Mike A.]

The "interference" that look like analog electrical interference goes away when it is in B/W...

I think it's still there, just not as apparent as when in color. You can still see the lines at various times, e.g.:


.

 

[wittaj]

Yeah but it is happening on what appears to be on an iframe and is worse in the color version. That is why I think it is something like backlight is on and over time the sensor is not adjusting as quick, or it is simply the sensor is starting to go out.

 

[robo65536ru]

Sample at daytime period. Seems to be fine.

 

[samplenhold]

I know he has not been on for months, but I wonder is @wopi82 has any ideas?