Tips for Fixing Ghosting and Artifacts on LED Video Walls

Ghosting and image artifacts are common problems on LED screens. They can affect image quality and viewer experience. You may see lines, waves, noise dots, image tearing, color blocks, or strange brightness areas. In some cases, parts of the image look duplicated or leave shadows behind.

These issues often appear during low brightness playback or high-load operation. The good news is that most ghosting problems have clear causes and practical solutions. This guide explains what ghosting is, why it happens, and how to fix it step by step. Click here to learn more how to troubleshooting an LED video wall

What Is Ghosting on an LED Video Wall?

Ghosting means the screen shows things that should not be there. For example:

• Light or dark stripes
• Ripple or wave patterns
• Fine noise or grain
• Local image distortion
• Color shift or uneven brightness
• Image trailing or shadow edges

In many cases, ghosting appears in dark areas of the image. It can also happen when content changes fast, such as video playback or camera feeds.

Start with the Control System Settings

First, always check the LED control system. Different processors use different image algorithms. Wrong settings are one of the most common causes of ghosting.

For NovaStar Control Systems

NovaStar processors include many advanced image features. However, if these features do not match the LED panel, artifacts may appear.

1. Turn Off Gray Compensation

Gray compensation improves low-brightness image detail. It works well below 20% brightness. It smooths dark areas and avoids color jumps.

However, when panel data does not match the algorithm, gray control can become unstable. This may cause ghosting, noise, or dark patches.

What to do:

• Turn off “Magic Gray”
• Save the setting
• Refresh the screen
• Check if the ghosting disappears

If the issue is gone, the function is not compatible with the panel. You can then try a lower value, such as 30%, instead of using the maximum level.

2. Disable Temperature Compensation

Temperature compensation changes brightness based on module temperature. In theory, this keeps colors stable.

In reality, inaccurate sensors or aggressive algorithms can cause flicker, brightness drift, or local artifacts. This is common in closed rooms or high-load setups.

Solution:

• Turn off temperature compensation
• Restart the screen
• Observe the image for stability

3. Match Color Depth with the Signal Source

NovaStar supports high bit-depth processing, such as 10-bit or 16-bit grayscale. However, many HDMI sources only output 8-bit signals.

If the processor expects higher bit depth than the source provides, data truncation may occur. This leads to banding, noise dots, or ghost shadows.

Best practice:

• If the source is 8-bit, set the system to 8-bit
• Avoid unnecessary up-conversion
• Always match input and processing depth

4. Reduce the Refresh Rate for Testing

High refresh rates are useful. However, they require stable power, good receiving cards, and high-quality cables.

If any part of the system is weak, scan interference or ghost lines may appear.

Recommendation:

• Set the refresh rate to 60Hz
• Test the image in stable mode
• Increase refresh rate only after confirming stability

For Brompton Control Systems

If you use a Brompton processor, ghosting is often related to configuration files.

Use the Correct Panel Description File

Brompton systems rely on official panel files. If the file does not match the LED module, timing and grayscale control may be wrong.

Action steps:

• Load the official panel file from Brompton
• Avoid using generic or third-party files
• Reboot and recheck the image

Disable HDR for SDR Sources

If the input signal is SDR but HDR is enabled, brightness mapping errors may occur. This can cause image tearing or ghosting.

Fix:

• Turn off HDR
• Use SDR processing for SDR sources

Try Disabling Calibration Data

Calibration improves uniformity. However, bad calibration data is a major source of ghosting.

When time is limited, disabling calibration is the fastest way to confirm the root cause.

Why Calibration Can Cause Artifacts

There are several reasons:

• Calibration files may be damaged during upload or storage
• Software updates may break compatibility
• Multiple calibration layers may conflict
• Operators may load the wrong batch file

When calibration is disabled, the panel returns to factory behavior. The image may be less uniform, but it should be clean.

If ghosting disappears, the calibration data is the problem.

Hardware Causes You Should Not Ignore

If software fixes do not help, hardware limitations may be involved.

1. Driver IC Performance

Low-quality driver chips struggle with fast brightness changes. When a pixel should turn off, it may not fully shut down in time.

This leaves residual light. As a result, ghost trails appear behind moving images.

This problem is most visible in low-brightness scenes. High-quality driver ICs provide better current control and cleaner grayscale.

2. Refresh Rate and Grayscale Mismatch

LED displays rely on PWM technology. If the grayscale clock and refresh rate do not match, pixel timing errors occur.

Possible results include:

• Flicker
• Image trailing
• Visible scan lines
• Camera banding

A refresh rate that is too low will also make ghosting visible to the human eye and cameras.

Final Troubleshooting Checklist

Before replacing hardware, follow this order:

1. Check processor image settings
2. Disable advanced functions one by one
3. Match signal format and bit depth
4. Test with lower refresh rate
5. Disable calibration temporarily
6. Confirm correct panel files
7. Inspect driver IC quality

Most ghosting issues can be solved before reaching step seven.

FAQ

Q1: Is LED video wall ghosting always a hardware problem?
No. In most cases, ghosting is caused by incorrect processor settings or calibration data.

Q2: Should I always use the highest refresh rate?
No. Use a stable refresh rate first. Increase it only after confirming system stability.

Q3: Does disabling calibration damage the LED screen?
No. It only removes correction data. The panel will run in its original factory state.