CNB BE3815NVR question on picture quality

[topspin 0]

I did an installation with 2 of these cameras. They are both located on the side of a building. The dvr board is Avermedia NV5000.

 

After installing camera #1, the client complained that the picture was a bit grainy or pixelated. To me, it seemed to be a lighting issue since the picture looks nice in the daytime but does degrade as it gets dark.

 

I then installed camera #2 and it looks a lot better than cam #1. The client really likes the picture quality of cam #2 and so do I. I want to try and fix cam #1 now.

 

Is lighting really the only issue here? The difference is just too big for it to be a lighting issue. This camera has jumpers. I had tested jumper #2 at home. If I set it to OFF, the IR led's did not turn on. I want the opposite though. I want the camera to go to IR mode right away when it gets a bit dark. The reason is because the picture quality is a lot better in IR mode.

 

I would be willing to give web access to the cameras to someone that has good experience in resolving picture quality issues like this.

[RickA 0]

Need to check AGC settings between the two cameras.

[CameraGimp 0]

I can't find an english manual but the specification shows DSS and digital noise reduction. Both of these could make a big difference at low light as could the lens level.

[rory 0]

You must goto the location at night to adjust the cameras, when installing a day/night application.

 

Showing us the video wont help, you need to physically go there, simulate the dark, then adjust the offending camera.

[topspin 0]

I'm not up on cctv lingo; what are 'AGC' settings?

 

I just got back from adjusting the camera. It was after 6pm and I still have the same problem. The picture just looks so pixelated and it also causes the fps rate on that camera to be much slower than the other 2 (I added a temporary internal camera).

 

I will re-do the connection since the picture was going dark while moving the cable. I'll also try another bnc connector. I hope it's just a bad connection. The supplier that sold me the camera has been helpful and has viewed the video. He said that it's a lighting issue but I just don't buy it since the image is always grainy, even in broad daylight.

 

The dip switch settings on both CNB camera are set identically (I left them all at the default down setting). There is an English manual on the cnb website: http://www.cnbtec.com/en/html/product/product.php?seqx_prod=341

[CameraGimp 0]

You say the picture is grainy even in broad daylight. This sounds like AGC noise. Automatic Gain Control is an amplifier for video. It should boost the video at low light. If you are seeing it during the day I would suggest the lens is closed down. Have a look at the DC level adjust.

 

You should turn agc off when you set dc level. Make sure to turn AGC back on after you've finished.

[rory 0]

Actually I never use AGC for day night apps at all.

 

Could be the IR is not coming on and its just too dark?

[topspin 0]

The IR is not turning on anymore since there is enough light from the reflection on the snow to keep the camera in 'night' mode. I'd rather it go into IR mode cuz then it looks really nice.

 

I did play with the potenciometer that adjusts the amount of light. I'm guessing this is the AGC gain. I boosted it a bit and it just made the image brighter but it still looks grainy.

 

In the Avermedia software, there is an adjustment for voltage. If I boost it, then the image does clean up a bit. But it's still a far cry from the quality on the other camera.

 

The only difference between the cameras is that one has a 40VA power adapter and the other has a 20VA adapter. The 20VA was the one that shipped with the camera. I had to return one camera and adapter though; when I got the replacement I just got the camera. So the supplier credited me on the adapter and I just got one here. I only found a 40VA and was told it would last longer than the 20VA. I might just try swapping adapters and see what happens.

 

If anyone is curious to see the cameras, pm me.

[Dr. CCTV 0]

Topspin,

 

You must dissable the D/N function in order to activate your illuminators at night. This camera does not have a AGC switch per se; rather, it is termed 'DC IRIS.' Only increase this a bit as it will boost the noise as well as the video signal. This will manifest itself as unwanted instability that appears to be crawling over your screen like a colony of ants; it's bad, so just tweek it a big. I would listen to your sales representaive because if he or she is like mine, they know their ****. Its funny, many times I call the manufacturer only to find out they know next to nothing about the product in question.

 

Doc.

[CameraGimp 0]

In my world DC iris level adjusts the iris of a DC lens. Setting it too low can result in AGC noise being visible but that only happens as a consequence of the lens iris being closed and it not letting enough light through.

 

I've no experience of this camera and it may be labeled incorrectly but DC iris level shouldn't increase the max gain.