CCTV manufacturers include an anti-flicker option in their software which is accessible via the recorders setup menu, or by connecting to the recorder via it’s ip address. You may need to log into each camera via ip address to enable this setting on each camera. The software option shifts frame capture point a very small amount in order to avoid capturing flickering caused by certain lighting sources. You may also try to change your recording frames per minute setting to a value that you cannot evenly divide into your main electrical frequency. For instance, if you’re in the USA you’re dealing with 60hz electrical power. Try and choose a frame rate to record on that will not evenly factor into 60 - ie avoid 5fps, 10fps, 15fps, 30pfs as each of these values may cause the camera to take a photo at the leading or falling edge that corresponds to the artificial lighting present at your location giving a flickering on your display.
If this does not solve your issue, continue - the solution will be listed here.
When designing a CCTV system, it’s important to know how much power each camera requires when IR-LED’s are illuminated, or when PTZ functions are implemented. These specifications are always available from a manufacturer as well they are typically printed on a label on the camera. Your power supply or PoE switch or integrated recorder will need to be able to provide at least 130% of the total wattage of all of your cameras. The extra 30% is important to consider as wire is not a perfect conductor and can present a more difficult pathway for electricity to flow depending on length, quality of connection, etcetera. You’re going to need to determine what type of cameras you have in your system, either composite or ip.
Composite will have a coaxial connection such as an BNC or RCA. An IP camera will have a modular RJ45 connector.
Flickering can be caused by an overload condition where your cameras need more power than your power supply can deliver; a DC power supply (composite cameras) or PoE switch (power over ethernet for IP cameras) or integrated PoE supply via some recorders, as some consumer grade camera systems supply their PoE camera power directly from the recording device. We see the flicker problem occur only at night because this is when the supply is overloaded as the current demand from the cameras is increased to support the IR-LED’s used to illuminate the field of view. This can often start happening after one or more cameras is replaced or new cameras are added when the cumulative total overall power requirement is greater than before.
Lets walk through how to check if this is what is going on. All of our testing will be done at night in the dark. If you have a recorder that is separate from the camera power supply make sure the power supply, recorder, and display are plugged into the same electrical supply outlet via a power strip. This may fix your problem, but most likely not. Follow the steps written below.
First, we want to see if a particular camera alone is causing the flickering due to a faulty camera or wiring drawing too much current. If each camera can be reconnected at night one at a time without recreating the flickering, we know the problem is not with a single camera. If you cannot recreate flickering with a single camera alone, try connecting that camera to each of the connection points available. If a single camera causes flickering or the flickering begins only when connecting to the same power port each time, suspect the port. If the flickering begins to occur no matter what port you use with a single camera but not every camera, you may have a camera that draws too much current for your supply to deliver, or you may have a faulty camera.
Second, begin to re-connect all the cameras one at a time, watching the display to see at what point the flickering returns. At the point your display shows flickering, remove the connection - this is the maximum number of cameras your power supply will support. Either replace the power supply with a higher current unit with greater capacity (such as a dedicated PoE switch with PoE+ or PoE (at) capacity) or add another power supply or switch for the remaining cameras. Don’t forget to connect the ground of each power supply together via the ground connection on the chassis of the supply. If the flickering begins immediately after connecting the first camera, continue to check each camera individually to be sure that the flickering occurs when connecting each camera alone to the power supply.
If all cameras flicker no matter what you try or how many cameras are attached to the supply, check and ensure your supply / PoE is rated for your country’s voltage and frequency. In the USA it would be 120/240vac 60hz while in Europe and Japan you’d want to be at 208–220v 50hz. There is often a small switch on your recorder, PoE switch, or composite power supply that enable you to choose the frequency. Your supply may be faulty, with leaky capacitors, a faulty transformer or switching supply, or your supply is not able to provide the level of current needed by your cameras. You can check this by disconnecting all cameras and connecting them to the power supply with short cables, remember to shut off the light in the room to trigger the IR-LED’s. If the problem goes away with all cameras connected this way, the problem is the length or type of wiring you’re using, or close proximity to a interfering source such as a metal halide ballast that is not grounded, or a metal halide lamp that has an unshielded socket.
If a single camera is isolated as causing the flicker when it is connected, and the flicker is present no matter if other cameras are connected or not, check that camera connection at both the camera and it’s power supply. Ensure the connectors are clean and not corroded. You may need to follow the wiring path to ensure nothing has pierced or cut the wiring. Try switching the camera with another camera that is working correctly. If the camera that was working correctly is now flickering when connected to the previously identified bad camera circuit, we know the problem is with either the wiring, connectors, or a device that is causing electrical or magnetic disturbance in close proximity to that wiring circuit. If the camera that is flickering is connected to a previously good circuit, and continues to flicker, replace the camera or note it’s current consumption - it may be a camera that requires more power than your system is able to deliver to any single device. In that case replace the camera or add a power supply that can provide the power requirements that particular camera needs.
While these steps may seem complicated, they’re really not. Just take them a single step at a time and you’ll figure this out and gain some valuable experience while you’re at it.