LED string light flickering

S

speedywrx

n3wb
Jun 30, 2015
17
14
Hello, I have a Hikvision POE 4k ColorVu camera that captures my back patio where the LED string lights are. I am getting a weird slow strobe effect. I have tried changing the frame rate from full, 22, 20, 18, 16, 15, 12, 10... and none of those values fix the strobing. I see there is also an I-frame interval option and I tried changing that a bit with no luck.

Anyone have any suggestions? Thanks.
 
If not able to address your issue with camera settings, consider:
Try to determine is the LED strings power supply is linear or switching. The string is likely switching off and on @ 60Hz, your AC power line frequency.
If it's a 12VDC power supply, try running it off a 12VDC battery, like from a riding lawnmower, etc. to see if it quits strobing.
If so, you can plan how to address it.
 
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Ok, I'll test it out this evening since it's too bright out right now. I do have them plugged into an outdoor outlet on my house, which I'd preferably like to keep that way since I have them connected to a z-wave dimmer tied into my smart house - would rather not have to fiddle with a battery. So if there is no fix for being plugged in directly to AC, I'll likely put up with that nuisance then. But I'll post back later tonight.
 
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speedywrx said:
I have them connected to a z-wave dimmer tied into my smart house - would rather not have to fiddle with a battery.
Click to expand...
Didn't know about the dimmer.....I'd bypass that first since it's quick and easy, plug LED string's power supply right into the wall and see if that "fixes" the stobing.
Most lamp dimmers and many solid state switches are triacs which turn on and off at AC's zero crossing, so that could be an issue right there.
 
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Exposure time, shutter speed, adjustments can help as well. You're having a problem because LEDs turn on and off in time with the AC waveform, 60 times a second. Any multiples of exposure time in relation to 60 will result in flickering.
 
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A low (very slow) shutter speed will fix it. I run across this all the time.

Frame rates have nothing to do with your concern.
I-frame rates have nothing to do with your concern.

Sometimes changing to 50 or 60 HZ will work as well - depends on led manufacturer, the leds used and the power supply used. But it is worth a shot to see if you can avoid really slow shutter speeds.
 
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Best to fix it with shutter speed. Some cameras changing the frequency will limit the amount of customization you can do in regards to other parameters like shutter speed - it may only allow slower speeds.
 
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I'm poking around the setting of the Hikvision NVR and I can't find anywhere to change from 60 to 50 Hz.. Still waiting for dark to test some things out. Screenshots of what I'm looking at:



 
alastairstevenson said:
Isn't that going to create a lot of motion blur on movement - the last thing you want on a security recording?
Click to expand...
Yep!
But if this phenomenon bothers him more than quality, submittable video....
 
No need to redact those "private" IP's or LAN IP's; it's your WAN IP we don't need to see.
My Blue Iris server LAN IP is 192.168.1.239, cams are 192.168.1.200 through .212
 
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As mentioned previously, no need to spend the time blocking out your LAN addresses.

You can list the private LAN IP addresses as it does not tell anyone anything - they are the same as everyone else. The IP address of your service provider for your WAN is what you don't provide...Everything on the inside past the modem is fine to put out. Everything on the inside, the local will fall under these ranges and you are not telling anyone anything about how to hack your system providing these ranges (basically any IP that starts out 10. or 172. or 192. are reserved for the "home side" of the service so every home internally will be within this same range):

10.0.0.0 – 10.255.255.255
172.16.0.0 – 172.31.255.255
192.168.0.0 – 192.168.255.255
 
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speedywrx said:
Hello, I have a Hikvision POE 4k ColorVu camera that captures my back patio where the LED string lights are. I am getting a weird slow strobe effect. I have tried changing the frame rate from full, 22, 20, 18, 16, 15, 12, 10... and none of those values fix the strobing. I see there is also an I-frame interval option and I tried changing that a bit with no luck.

Anyone have any suggestions? Thanks.
Click to expand...

I needed to change my exposure settings to eliminate LED street light flickering. This worked for mine.

1662951514280.png

When I went higher than 7 ms, the flickering became more obvious for my particular light. I can run at 7 ms at night because I have 300W of LED lighting on the pole by this camera. I never touched any setting other than the exposure range to nearly eliminate the LED strobe effect.
 
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I noticed your iframe is at 25fps but you're using different frame rates to that.

You're iframe should match your frame rate. Try 15 for both. Not saying its going to solve the flickering but it will help alleviate any other issues. It needs to be kept 1:1.
 
Ok, last night I tried removing the dimmer and powering it via a battery inverter (lawnmower battery) and it did not solve anything. I still cannot find the settings for individual cameras. The website says there should be a URL under the "connect" column (in my last screenshot), but mine is blank. Maybe there is a different firmware I can find to upgrade the cameras/NVR to expose those settings...?
 
I updated the firmware on both the cameras and NVR (both Hikvision). Still can’t access the camera GUI remotely. So I lugged my monitor into my network closet and directly attached it to the NVR. I was able to see camera settings, no Hertz options, but I did find this that I will play with tonight. Set at 1/25 exposure by default.
 

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