Ghosting or ghost effect: what it is and why it seems on monitors

If you are into the world of computing, especially gaming, you have probably heard of ghosting or the ghost effect of screens. In this article we will explain as best we can what this effect is about and what it causes on our monitor. In addition, we will help everyone to identify it on our screen with a simple test and where we will explain the different types of ghosting.

Index of contents

What is ghosting or ghost effect

Explaining in detail what ghosting is is not such a simple task, mainly because over time it has manifested itself in different ways depending on the imaging technology used. Let's try to see it in parts.

Ghosting or burned screen in CRTs

Ghosting has its origins in the first CRT monitors that appeared on the market, those whose imaging technology was based on phosphor panels that were illuminated by an electron beam called a cathode ray tube (CRT).

In this case, it is called ghosting, burn-in screen or screen burn, due to what happened with the phosphor panel. On these screens, non-uniform use of pixels, such as displaying the same static image for a long time or always the same images and transitions, caused ghosting. In them, basically a ghost image was created that sometimes was even permanent on the panel due to the wear of the phosphor luminosity in the specific places where this image was. It occurred when making very uneven use of the panel.

What this effect does is technically burn certain areas of the screen, which is sometimes so serious that even with the monitor off we can see that image physically recorded on the screen. This was a big problem especially on monochromatic monitors that used command terminals, since almost always showing letters on a green or black background caused them to literally stay recorded.

Ghosting or phantom effect on Plasma, LCD-TFT and OLED monitors

After the CRT monitors, the first LCD and Plasma screens appeared, where the latter also suffered a very similar type of burnout due to their imaging technology, and that is why practically all current screens have LCD-TFT technology. or liquid crystal with thin layer transistors or now OLED organic light emitting diodes.

Currently, these LCD screens are much less susceptible to ghosting than we have talked about, although it is true that we can see this screen burn-in on screens that are lit 24/7 with the same image, for example, airports, and other spaces public. In them, burning is manifested due to the degradation of the pixels and the luminance that can show if they are light emitting or the return to their base state if they are of the TFT type with backlight.

What do you think screen savers are for?

The screen saver that we have seen so many times in Windows 98 and XP precisely served to not have a continuous image on the monitor continuously when we left it on. If you remember, these screensavers always gave us a continuously moving image to ensure that all the pixels or phosphor cells were in constant change, thus preventing the phosphor panel from burning.

If you are such a lazy user that you decide to leave your screen, whatever it may be, always on, even if you are not using it, still today we can have the mythical screensavers in our Windows.

Currently the use of screensavers has been replaced by simply automatically turning off the screen of our PC, more effective and in addition to saving energy.

The term ghosting related to gaming

In the domestic sphere, we are practically exempt from this phenomenon of screen burning, and we refer to ghosting in a somewhat different way, and closely related to the image quality of the monitor.

For a typical use, we do not expect to have an image fixed too long on the screen, so the ghosting effect is only transient in them, lasting minimal periods of time that are rarely noticeable, except in a highly trained eye. We can call this new ghosting transient image persistence. This phenomenon causes that in certain fast transmissions of an image a small retention of the previous image or frame occurs. Let's say that it is like a wake space that sometimes manifests itself together with a dark or light contour or crown as we will now see, due to the accumulation of electric charge in each pixel.

This is most often manifested when bright, sharp objects are displayed under a black or darker background. What we generally perceive is a kind of trace or blurring of the image mainly due to a slow screen response time and also a low refresh rate. This is quite annoying for competitive gaming, since having a wake image makes the accuracy when shooting worse and also our sight suffers and tires more.

Identify ghosting on your screen

In the case of screen burning ghosting, we will be able to notice it quite clearly if we place a black background on the panel with this ignition. If we see a static image in the background continuously, it may mean that certain pixels have been degraded or burned. Be careful, then we will see that this sometimes has a solution, so all is not lost.

But if what we intend to do is look for the presence of temporary ghosting, the task can be somewhat more complicated and will also depend on the configuration of the monitor, GPU and our own view.

One of the most widespread tests on the network to detect temporary ghosting, and which is also quite well explained on the site, is the one on the page testufo.com, where an image is shown at 960 pixels per second that runs through our screen. The web shows explanatory results with the help of captures by a high-speed camera that records the pixel transition. In it, we can make a lot of image and speed modifications to see the different situations and thus test in depth the response of our screen.

These are the effects that we must perceive with this test

To begin with, ghosting can be identified in two different types. In a first case with a black trail against the direction of movement, and in a second case with a white trail. This is accompanied by a very blurred image that does not belong to the image itself. This may be due to a low panel response time. The better the response, the faster the pixels are turned off and on and the less ghosting there should be (not always the case). This we will have to verify with our own view, following as far as possible the UFOs that pass through the screen.

Ghosting effect with black and white trail

We should not confuse it with motion blur, since this phenomenon is not a ghosting problem, but rather a low refresh rate and caused mainly by our eyesight. In fact, if we take a camera and photograph the screen, we will not see such a blur on it, but everything is produced by the slow refreshment and our eyes if it is a 60 Hz screen for example. The more frequency, the less blur, this is basic. This we will also have to perceive with our eyes.

Blur effect

With a static camera and taking a photo, we will be able to see the transition effect of the pixels and how the PWM control that some LCD monitors have to act to modulate the brightness of the screen. Keep in mind that in this way we do not detect ghosting, it is only a capture in an instant of time in which we see pixels turning off and on. Even if we make a slow motion video we will see this transition, but not the ghosting.

Transition effect of frames captured by a camera

How to fix temporary Ghosting

Of all the images that we will see below, only the 3rd and 4th will be the ones without ghosting. In the first we have the effect of darkness, while in the following we have the white border.

Using the technology built into the monitor

One of the ways to try to fix ghosting is to modify certain parameters of our monitor through the OSD panel. Most current gaming monitors that have a medium / high range have their own technologies that eliminate this effect, for example, Asus is Trace Free and many others are simply called Overdrive or similar.

We must adjust and select the different options to see if the results vary and we perceive a better image without ghosting.

Modify response time

Response time is measured in milliseconds, and is the time it takes for the monitor to receive the image and change the color of the pixels. Many monitors also have an option to change the response time, of the screen (note, we do not talk about the refresh rate).

We can select different configurations to see, once again, if the image improves or worsens. We can change colors and speeds of UFOs to see certain scenarios.

Adjust refresh rate, and dynamic refresh technology

The refresh rate can also have an influence on ghosting, especially with flickering or flickering, and the image blur effect. As before, we will modify these values ​​in the OSD if possible to improve the quality of the moving image.

Alongside this is dynamic refresh technology, which can be AMD FreeSync and derivatives, or Nvidia G-Sync, owned by Nvidia. It has a lower incidence in ghosting, but having it activated will improve other aspects such as those previously mentioned.

Updating firmware and drivers

Another way to alleviate these effects is to search the manufacturer's support page for firmware updates for the monitor, if it is a software driver from the system. Or in the more generic case, if there are specific Windows drivers that allow better control of it.

On the other hand, we must also resort to updating the video drivers of our graphics card and verify that all connections are correctly carried out.

Checking connections and wiring

Many times, a poor quality of the cable will cause the image to lose consistency and especially phenomena such as flickering and ghosting due to a bus that is not stable or limited. Above all, higher performance monitors such as 4K at high frequencies suffer more with a bad cable, so we should refrain from buying the € 3.50 DisplayPort or HDMI that is in the Chinese bass of our house.

Possible solution for permanent ghosting

As for the permanent ghosting of an image on the screen, we can give a difficult solution unless it is a kind of screen controller bug or similar.

To do this we will use a program called PixelHealer, whose function is to subject the monitor to a series of color tests to revive and return those pixels that may have been left with a certain color or fixed brightness to the normal state.

It will be as simple as downloading it for free from its official website, installing and running it. After a process that lasts 60 minutes of continuous flashing of the panel, we can verify if the ghost image continues on the monitor or has been removed. It is not a 100% effective solution as there are unrecoverable panels.

Conclusions about ghosting

As we can see, it can be considered that there are two types of ghosting that can be perfectly manifested in current monitors. Although it is true that LCDs have a very controlled burn-in issue. We hope that this explanation and advice have been useful for you to get to know ghosting in depth.

We finish with some articles that we consider useful:

Does your monitor have ghosting ? Could you fix it? Tell us your gaming experience with the monitor you have, and if it has ghosting or any other important problem