stu007 0 Posted January 13, 2009 (edited) Hi. I'm in the process of installing CCTV into a store. It will be a 4 camera wired system with a Dvr. I've currently got 3 cameras installed, 2 on the shop floor and 1 in a store room. On 1 of the shop floor cameras I am getting interference on the image. The interference is in the form of wavey scrolling bars the roll diagonally across the image. The cable for this camera goes across the store above the atificial ceiling. Any ideas what is causing this inteference? Thanks, Stuart. Edited January 22, 2009 by Guest Share this post Link to post Share on other sites
coolie11 0 Posted January 13, 2009 Are you powering all cameras and DVR from the same power source / location? What type of cable are you using? Share this post Link to post Share on other sites
stu007 0 Posted January 13, 2009 I'm using pre-made BNC cables. I've got 1 5amp power supply with a splitter for the cameras, and a seperate power supply for the Dvr. Both power supplys feed from the same wall socket through a 4 way adapter. Share this post Link to post Share on other sites
Ted 0 Posted January 13, 2009 It could be interferences from a lighting source close to the cam or a high current cable close to the cam or cam-cable somewhere on the way to the DVR. Maybe a DECT base-station close to the camera, unlikely though. Are there any joints on the cable? Try to move the cable on a few locations and see if the interference changes in any way. Share this post Link to post Share on other sites
stu007 0 Posted January 14, 2009 The cable goes from the Camera to Dvr in one strech, it travels about 6m - though the cable is 20m long so their is a coil of excess. I will try connecting the camera direct to a monitor, that is close to the camera and see if that results in a improvement. That should give me an idea wether the interference is from the camera or cable. I will report back, Thanks. Share this post Link to post Share on other sites
scorpion 0 Posted January 14, 2009 Are you using a BNC to RCA adapter to connect the camera to the cable? If yes, then replace that with another one to see if that clears it up. If no, then you have a bad cable. Bend the wire at both end where the wire connects to the bnc connector. See if your video pops in, and out as you wiggle the wire back, and forth. Share this post Link to post Share on other sites
stu007 0 Posted January 21, 2009 Here is a example screenshot showing the diagonal distortion. The image is at frame resolution 720x576 at 6fps, yet the image isn't that clear to me. Is that down to the compression on the DVR? Share this post Link to post Share on other sites
stu007 0 Posted January 25, 2009 I have tried numerous combinations to isolate the interference. Tried another cable - Interference still present Tried Camera straight into monitor - Interference still present Moved camera to different location - Interference still present I have come to the conclusion that the camera itself is causing the distortion. When the camera is disconnected, then reconnected it takes 30s or so for the intereference to appear. Once it first appears it then progressively gets worse for a minute, almost as if 'some charge' is building in the camera. Have I just got a faulty camera? Share this post Link to post Share on other sites
scorpion 0 Posted January 25, 2009 Have you swapped one of the other cameras with this camera to see if the problem "follows" to the other location? Side note: I would not use such a wide angle camera for a front door shot. Does this camera have WDR when the sun is shining through the door, and windows? Share this post Link to post Share on other sites
stu007 0 Posted January 30, 2009 I have swapped this camera with an identical one Ihave located else where. The interference has 'followed' the original camera to the new location. Share this post Link to post Share on other sites
scorpion 0 Posted January 30, 2009 I will have to assume that the camera is under a warranty, and that you can return it. Sounds like you are doing a great job troubleshooting. Share this post Link to post Share on other sites