Is your security camera showing horizontal lines on the video feed? These lines, sometimes known as a smear or blooming, could make it difficult to see anything on the screen and will decrease the efficiency of your security system.
Sometimes these horizontal lines wash up sections of the video and keep rolling up, sometimes they just flicker or stay in the same position. Either way, you need to address the issue as soon as possible because the footage may become unusable if there’s an incident.
There are a lot of reasons that could make surveillance cameras show horizontal lines on the screen. It could be a hardware issue such as bad cables or cameras, or even software-related. In this article, we will show how to fix the issues of horizontal lines on security cameras. Keep reading the following causes and solutions.
Fix: My security camera shows horizontal lines
This issue always shows on HD analog cameras such as regular analog, HD-CVI, HD-TVI, AHD, HD-SDI, it never shows on IP camera systems (that use NVRs). Usually, the rolling lines move from top to bottom or vice versa and in certain cases vertically from left to right.
Generally speaking, the issue may be caused by local interference that causes ground loops problems. Sometimes it is caused by a faulty power supply that doesn’t power up the camera correctly.
Another frequency, the cameras are designed to work on certain frequencies such as 50Hz or 60Hz, make sure the frequency settings are set properly. In other scenarios, the IR LED lights of the cameras are struggling and drawing too much power from the camera, which causes the camera’s sensor to struggle.
Check loose cables
If the coaxial cables are loose and the connection is not fully closed then the camera may show horizontal lines on the screen. Inspect the camera and the DVR side to ensure that the BNC connectors are fully plugged in.
If the connector is wonky or doesn’t look firm, then you may need to redo the connection. Splice the cable carefully and then terminate the BNC connectors on both sides. In some cases, the horizontal lines show up on old cabled runs, especially the ones used outdoors. Check out your cables and ensure the runs are correct.
Fix the light source
A factor that causes the horizontal lines in security camera videos is the light source hitting straight to the camera’s sensor. If light falls directly on the camera, then the transmitted video feed may not be clear and may result in horizontal lines.
If the camera’s sensor gets hit with an extra bright light then the pixels get overwhelmed and the horizontal lines that you see are basically electrical interference of the light sensor. Another effect is the famous rolling lines on the video.
To solve this problem, inspect the placement of the camera and re-angle it to avoid any light sources hitting the camera directly. For example, you can point it a little bit down, or move to a different installation spot altogether.
Additionally, you may adjust the light source, make it weaker or move it somewhere else, basically, you need to reduce the light intensity close to the camera. Another solution is to use dome cameras with darkened glass.
Try a different camera
In some cases, your camera is simply bad and you can’t do anything to have it fixed. Especially, the extremely cheap cameras are manufactured with poor chipsets and materials that deteriorate after a few weeks or months. If the chipset is subpar, the picture quality will be poor.
A bad camera is considered a camera with a low-performance sensor, low resolution, low pixel count, etc. We’d suggest trying a new camera that meets your image quality requirements and then check out if the horizontal lines persist.
Moreover, you can try a camera with WDR or Widen Dynamic Range or BackLight option. Make sure to enable it on the settings. Additionally, you try a high-end CMOS sensor camera that has less chance of showing horizontal lines.
Check the power supply
The faulty power supply may cause image issues. When the power supply cannot provide enough power for the camera, it means the sensor struggles and underperforms. This performance issue can be exhibited as rolling lines on the feed.
Not just that, but the frequency of the power supply should match that of the camera. If the cameras are PAL or NTSC, the frequency should be set correctly on the settings to match the power supply.
If the power supply is not working 100%, then you may need to replace it with a new one. Also, ground the connection, only one end must be grounded to dissipate the RF to the ground.
Check Cat 5 or Cat 6 cable shield
Another common cause for horizontal lines in security cameras is a problem with the Cat5 or Cat6 shield. Check out if the cable’s shield is touching any equipment, if so then it may cause interference. This is especially the case when installers install HD over coax cameras using RJ45 cables.
Disconnect the system connections and check the Ethernet cable of your system, sometimes the Rj45 which is used at the cable ends has a grounded problem.
Use CCTV ground loop isolator
The easiest and most cost-effective way to remedy a ground loop problem that causes horizontal lines is to use a ground loop isolator transformer. This device connects anywhere between the head end and camera on the video cable and isolates the video ground.
The ground loop isolator transformer is relatively inexpensive and simply connects via BNC connectors between the camera and end device. So, if the ground loop is giving you headaches, purchase a ground loop isolator and get it fixed.
Horizontal lines in security cameras are a problem that needs to be addressed as soon as possible. These rolling lines may render the footage useless and that will compromise your security.
Follow the suggestions listed above, start by checking the wires and ensuring that the connectors are not loose. Then inspect the power supply and light sources. In some cases, the camera is simply bad and you need to replace it with a new one. If you’re looking to improve your security system, take a look at our recommendations on this link.