LED Dimmers interfering with IP CCTV cameras?

[ebourlet 0]

At a new office that we are using Pelco Sarix cameras we have a problem with scroll bars showing up on the cameras when the LED lighting is dimmed below full brightness. These are IP cameras and I suspect that it has to do with the LED dimmer using a high frequency pulse with modulation scheme that results in the lighting actually flashing at a rate that is not perceptible to the human eye but is to the camera resulting in a beat pattern between the camera and the lighting. Please don't respond with things like "it a ground loop" .... If you have first hand experience with a similar situation involving LED dimmers and CCTV I would appreciate hearing your thoughts on how I can mitigate the problem.

[ak357 0]

At a new office that we are using Pelco Sarix cameras we have a problem with scroll bars showing up on the cameras when the LED lighting is dimmed below full brightness. These are IP cameras and I suspect that it has to do with the LED dimmer using a high frequency pulse with modulation scheme that results in the lighting actually flashing at a rate that is not perceptible to the human eye but is to the camera resulting in a beat pattern between the camera and the lighting. Please don't respond with things like "it a ground loop" .... If you have first hand experience with a similar situation involving LED dimmers and CCTV I would appreciate hearing your thoughts on how I can mitigate the problem.

 

Something like this ?

[ebourlet 0]

Yes upon further research I believe it is caused by a PWM dimmer they should have used a CWM dimer

[ak357 0]

Yes upon further research I believe it is caused by a PWM dimmer they should have used a CWM dimer

 

I know Pulse Width Modulations

what is CWM ?

[GrouchoBoucho 0]

see if the camera has a "flicker control" setting... then try playing with the shutter speed.