Subscriber Discussion

Flickering Daytime Images?

UI
Undisclosed Integrator #1
•Apr 11, 2018

I have a problem and not much help. I have a Savvy Tech system or Dahua with 16 Channel NVR full of these cams. 8- Model Number: DH-IPC-HFW54A1EN-Z (motorize lens) 8- 4MP DH-IPC-HDW44A1EN (fixed) there is an ever so slight undulation more so on the motorized zoom cameras and not as much with fixed lens but a few have same issue. The new camera I put in as replacement worked fine with a ever so hardly noticeable scene change. It is not a flickering video problem hard to explain, WDR setting help significantly but still visible. 

I am going back to do the following: 

Manually set Iris get it off auto... test cameras with issues off NVR on laptop thus eliminate NVR HDMI output...What else should I try?

UM
Undisclosed Manufacturer #2
•Apr 12, 2018

Post a video clip. See if there is an anti flicker or 60hz power line frequency lock setting  Or flickerless mode option.  Many cameras have a setting for it. 

Check out the panasonic YouTube video I posted.a few days ago for an example. 

UI
Undisclosed Integrator #1
•Apr 12, 2018

SYSTEM box is checked for "outdoor" currently with 50-60-Hz as options...In Dahua PDF it explains the following.  60Hz: When the current is 60Hz, system can auto adjust the exposure according to the environment brightness in case there is any strip. So what does strip mean?

Is it similar to smear whereas my shutter is set to auto and in bright scenes shouldn't it go as high as possible?

UI
Undisclosed Integrator #1
•Apr 13, 2018

well went to ipcamtalk for help on this issue I posted and got banned...Friday the 13th in full swing and I'm an idiot for selling product's I can support.

 
(1)
U
Undisclosed #3
•Apr 13, 2018
In reply to Undisclosed Integrator #1

this made me laugh hard....  not at you, but with you.  ;)

I've seen ground loop/power issues cause what you describe.... the cameras that require the most power (motorized) show the most obvious symptoms based on your description.

a video clip would help - as mentioned above by UDM2.

 

UI
Undisclosed Integrator #1
•Apr 13, 2018

Flicker video

UI
Undisclosed Integrator #4
•Apr 14, 2018
In reply to Undisclosed Integrator #1

definitely a video is worth a thousand suggestions!

Avatar
Ethan Ace
•Apr 13, 2018

That's caused by a long I-frame interval. It's essentially artifacts caused by the moving foliage building up in P-frames until the next I-frame is sent and it clear. Check out our report Test: H.264 I vs P Frame Impact for examples.

In the web interface, make sure I-frame interval matches whatever frame rate you're using. So if you're looking at 10 frames, I-frame interval should be 10. If you're at 30 FPS, I-frame interval should be 30, and so on.

UM
Undisclosed Manufacturer #2
•Apr 14, 2018

I usually refer to it as a pulsing effect. While the framed rate = I frame interval is a good rule of thumb it does be pend in the scene  There are times where you need a longer  or shorter intervals so your eye doest catch it. 

UI
Undisclosed Integrator #1
•Apr 14, 2018

Thanks Ethan I'll adjust according and appreciate your candor and not referring to me as inept. I'm not the sharpest knife in the drawer, just here to learn. I did take the camera course years back and never finished. I missed the I&P Frame part, guessing so?

Funny thing is I told IPcamtalk I was doing my MASTER THESIS in: Automatic exposure control in network video cameras and Distortions caused by a rolling shutter...they didn't believe me...

 

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