Security cameras have a common issue of ghost image formation due to a signal from a different device or a camera. People may have observed an unusual activity like a ghost image or scary things caught on camera but they are not sure whether it is really a ghost or camera fault. In February 2021, dailymail.co.uk reported that a couple in Aintree Merseyside was shocked when they caught a “ghost bride” on their surveillance camera.
So, you might think about what causes ghost images on security cameras?
There are several reasons behind this phenomenon like lens flare, slow shutter speed, video compression and digital noise reduction, etc. We will discuss almost all the reasons behind this phenomenon and how to fix it.
1. How to define a Ghost Image?
Ghost images are formed when a security camera picks up the reflection resulting in a blurry image or two images overlapped. In some cases, the camera forms a ghost image due to reflecting off its lens.
There are some reasons behind ghost image formation on security cameras especially at night:
- When there is a glass or mirror placed opposite to the camera it can reflect the camera’s image back.
- If the camera lens is dirty, reflection might happen due to lens.
- If the camera sensor has a defect then also ghost image can be formed.
2. What Causes Ghosting On CCTV Cameras? Almost All Reasons Explained
2.1 Camera Problems
Camera settings need to be done in a professional way to get the desired results as many things are working at a time in security camera settings. There are many other reasons but camera settings are the most important cause.
Below are a few camera settings that if not done correctly can cause a blurred image or a ghost image:
2.1.1 Frame Rate and Slow Shutter Speed
Shutter speed is the time taken by a camera sensor to take a picture. Shutter speed must be in a fraction of seconds. On the other hand, frame rate is the number of images captured per second. Slow shutter speed allows the sensor to capture more than enough light.
Too slow shutter speed and frame rate can cause ghost images more often when the object is not still. For example, if a bike or any other vehicle is moving very fast, the camera will capture fuzzy footage that will look like a ghost image. A standard frame rate for security cameras is between 7.5 and 15 FPS and shutter speed is 1/48s or 1/60s.
2.1.2 Digital Noise Reduction, Brightness and Contrast
You heard noise as a hearing process, but did you know that you can see noise as well?
Sometimes there are unusual variations in the color or appearance of an image that is known as noise in an image.
A setting called Digital Noise Reduction(DNR) which involves the removal of visible noise from the picture. Correct DNR setting enhances the image’s look and appearance. But it can cause orbs on camera if DNR is set at a high level.
2.1.3 Wireless and Wiring Issues
Wireless cameras, if placed far away from the router, can cause unusual activity. Make sure your camera is placed at a standard distance from the router. Loosely installed wires or faulty wiring can also cause double-image issues.
2.1.4 Updated Firmware
Always check for a firmware update for your security camera from your service provider’s website. Security cameras need firmware updates to fix a bug, which includes flickering issues causing ghost images.
2.2 External Factors
There are some external factors other than camera problems that can be a reason for security camera ghosting. Regular upkeep can aid in overcoming problems like video disruption and security camera ghosting.
2.2.1 Lens Flares due to Strong Light
When strong light hits the camera lens, a flare can form, causing image issues. Light can come directly from the sun, a reflecting surface, or any other source. Obviously, no one deliberately sets their camera towards the sun but light rays can hit the camera sensor directly or through a reflecting surface of an object. It scatters the light in all directions forming a double image of that object.
2.2.2 Infrared Glare
You need infrared security cameras to keep an eye on your property at night. In the case of infrared cameras, correct placement is compulsory. If placed near a pilar, mirror, or a reflecting surface, infrared light coming from the camera may hit the mirror and reflect back to the camera sensor. This can cause a double image effect also called a ghost image.
2.2.3 Dust
Ghost-like images can also be formed when there is dust on the camera. Dust on the camera can cause the image to blur or unclear. In changing weather conditions, mist on the security camera can also form blurry images which can lead to orbs on security camera.
2.3 Some Other Factors
2.3.1 Compression Effects
Sometimes, to save storage space, people use compression tools to compress the video recorded by a security camera. But high compression leads to unnatural phenomena like ghosts on security cameras.
This unnatural phenomenon is ghosting in which compressed images have a double effect. A fast-moving object accelerates this phenomenon.
2.3.2 CRT Monitors Burn-In
Ghost images can occur by screen burn-in when you are watching the video footage on an old CRT monitor. When a clear image is shown on a CRT monitor for a long time, it can be burned in and form a ghost-like image.
3. Effect of Ghosting On Security Camera System
Ghost images are not just scary but they can have adverse effects on your security camera performance in many ways:
3.1 Unclear Footage
Ghosting in security cameras may eliminate the important scenes of footage, making it difficult to see objects, persons, and scenes of interest.
3.2 Misunderstanding
Unclear images can easily lead to misinterpretation. For example, if a security camera ghost image is considered for an outsider, it can cause an unimportant alarming situation or panic environment.
3.3 Evidence Problems
If a video evidence contains unclear footage or ghost images, it will be more difficult for a lawyer to convince the judge in an incident of crime. So, it devalues the security system.
3.4 Bad User Experience
Users watching video footage that contains ghost images may experience eye irritation and frustration.
3.5 Repair Costs
If there are continuos cctv camera image problems, it can lead to more repairs or even parts replacement that will increase the repair costs.
4. How to Avoid Security Camera Ghosting
If you are experiencing ghost images in your security camera footage, below are some helpful tips to solve your issue:
4.1 Set Night Vision IR
Adjust the IR intensity to a low level to reduce reflection, if you notice cctv ghosting only at night then your IR source may be too bright. Set your camera position also to avoid mirrors or any other reflective object.
4.2 Install Lens Hood
It will reduce the light coming towards lens, hence avoiding lens flare. Also, clean the camera lens.
4.3 Adjust Shutter Speed
Increase your shutter speed, it will reduce the blur in the video of a fast-moving object. But this will increase the video file size because more light is needed for this purpose.
4.4 Reduce Compression
To minimize compression effects, increase the video encoding bitrate. This will decrease ghosting but uses more storage space.
4.5 Change your Monitor
If you are using a CRT monitor then you must shift to a LCD monitor or a computer monitor.
4.6 Alter Camera Position
Change your camera position if it faces reflective surfaces to avoid flare or IR reflections.
4.7 Check Wiring
Poor wiring can cause signal problems that lead to ghosting. Replace any damaged cables and rewire the cables carefully.
4.8 Clean the Lens
Ghost images could be formed due to raindrops, mist, and dirt on the camera lens. So, clean the lens properly.
4.9 Update Firmware
Contact your manufacturer for any firmware updates that may reduce image or video distortion.
5. Conclusion
Hopefully, you got the answer to “What causes ghost images on security cameras?”
Ghost images can be caused by various factors like digital noise reduction, IR glare, dirt on the camera, and compression effects. And these have adverse effects on security camera systems like increased maintenance costs, legal issues, blurred footage, and bad user experience.
You can reduce ghosting by adjusting the camera position, cleaning the lens, setting the night vision IR and using quality cables, etc. If the issue persists, contact any trusted security services provider.
6. Frequently Asked Questions(FAQs)
Why are my security cameras ghosting?
Security camera ghosting is mostly caused by wiring issues, inadequate lighting, digital noise reduction, and slow shutter speed.
What is a ghost image on a camera?
A ghost image on a camera is an unusual picture that is formed when there is more reflections coming back towards the camera lens.
What causes ghosting in a digital image?
Light reflection is the main reason behind ghosting. Ghosting mostly occurs when there is a strong light source in front of the camera.
What causes double image on CCTV cameras?
Double image on CCTV cameras could be caused by loose wiring connections or reflection issues.
How to prevent ghosting on camera?
You can fix ghosting issues by adjusting shutter speed, installing a lens hood, reducing compression, altering the camera position, or changing the monitor.