FAQ For C-Series: Why is my Oncam C-Series image grainy, pixelated, flickering, or showing scrolling lines?

If your Oncam C-Series camera is displaying a grainy, pixelated, or flickering image, or if you notice horizontal scrolling lines, these symptoms are usually related to firmware version, power frequency settings, HDR configuration, or stream profile parameters. Follow the steps below to correct the issue.

1. Confirm the Camera Firmware Version

• Always ensure your camera is running the latest firmware version.

• Firmware updates often include imaging improvements, noise-reduction refinements, and video encoder optimizations that reduce pixelation, flicker, and compression artifacts.

• Updating first ensures you’re troubleshooting with the most stable and optimized version available.

A separate article covering Upgrading/Downgrading C-Series Camera Firmware can be found here

2. Check the Power Frequency

• Navigate to Video/Audio > Imaging Settings.

• Set the Power Frequency to match your region:

  • 60 Hz – for United States, Canada, and most of the Americas

  • 50 Hz – for Europe, Asia, Africa, and other applicable regions

• This setting helps eliminate flicker or scrolling lines that appear under fluorescent or LED lighting.

3. Disable True Detail HDR

• Under Video/Audio > Imaging Settings, locate True Detail HDR and turn it off.

• In certain lighting environments, HDR can cause parts of the image to appear noisy or grainy, especially in areas with low contrast.

• Disabling HDR can sometimes result in a smoother, more consistent image.

4. Verify the Media Profile Resolution and Frame Rate

• Go to Video/Audio > Media Profiles

• Confirm the selected profile is configured for the highest available resolution and maximum frame rate (FPS) supported by your network or VMS/NVR.

• Lower-resolution or reduced-FPS settings can cause blocky or pixelated motion.

Summary