Monitor ghosting is a name given to pixel trails that appear during fast-paced motion as a result of slow pixel response times. You can fix ghosting using the overdrive setting in your monitor’s menu, but beware of inadvertently causing pixel overshoot instead.
Do you see trails or blurring on your monitor during fast-paced motion or games? Ghosting can affect LCD monitors and televisions, but you may be able to rectify it with a simple setting. Here’s how.
What Is Monitor Ghosting?
Monitor ghosting refers to visual artifacts that follow moving objects, particularly prevalent when gaming or displaying other fast-moving content. You might not notice ghosting in normal desktop use or slower-paced games, but it can be distracting when you’re playing first-person shooters, racing games, or even scrolling quickly on a web page.
Some displays may be more prone to ghosting under certain conditions, for example in especially dark scenes. This can cause a loss in shadow detail and turn large parts of the screen into a smeary mess. On top of being frustrating to deal with, ghosting may contribute to eye strain over long play sessions.
Ghosting can affect any type of LCD panel, including monitors and televisions. It’s more common on VA-type panels, which are the main LCD panel types used on televisions. Ghosting shouldn’t be an issue on OLED panels but self-emissive displays may instead suffer from a form of temporary (and potentially permanent) image retention on static elements like health bars or news tickers.
What Causes Monitor Ghosting?
Monitor ghosting is caused by slow pixel response times, where pixels aren’t able to cleanly change from one color to another in good time. The problem is more noticeable at high frame rates, where frame times (the time in which a new frame is delivered) may be faster than the monitor’s response time.
Monitor manufacturers often advertise, alongside other monitor specifications like contrast ratio and refresh rate, a monitor’s response time in milliseconds. You may find these figures listed as “GtG” (gray-to-gray) and “MPRT” (Moving Picture Response Time), and both refer to different metrics.
GtG describes how long it takes a pixel to change between two colors. MPRT describes how long a pixel persists on the display. In both instances, a lower number is desirable. It’s possible to have a fast GtG value and a slow MPRT value, which may cause ghosting to appear on your monitor.
Blur Busters has an excellent explanation of how GtG and MPRT interact, what other factors affect these values, and how manufacturers attempt to solve the issues of image persistence.
Since these values are used interchangeably and often without context by monitor manufacturers, it’s advisable not to rely on a single advertised response value alone when making a purchase. We’d recommend reading reviews of any monitors you’re thinking of purchasing on websites like RTINGs to see if ghosting is present and (if so) how bad it is. You can also consult our roundups of the best monitors, best gaming monitors, and best ultrawide monitors.
Run a Ghosting Test to Identify the Issue
If you’re already seeing ghosting or pixel trails when playing fast-paced games, you’re already aware you have an issue. You may also want to run a ghosting test on your monitor. This is handy if you’re in the process of testing a monitor out in a showroom or thinking of buying something second-hand that you can get your hands on before you buy.
Use the Blur Busters UFO Ghosting Test to perform a ghosting test. Use the “Speed” drop-down menu to adjust the pixels-per-second, to simulate slower or faster on-screen motion. If you see pixel trails that are consistent with ghosting, you have identified the issue.
This test may also show up other artifacts which can appear when you try to fix monitor ghosting, so you’ll want to consult the test to see if the remedy below strikes a balance that you’re happy with.
How to Fix Monitor Ghosting
You can attempt to rectify monitor ghosting by using your monitor’s overdrive setting. By using higher voltages on individual pixels, response times can be improved and ghosting may be reduced or disappear completely. Different manufacturers have different names for overdrive settings, so you may need to dig through your monitor’s built-in preferences to find it.
Look for labels like Overdrive, OD, Response Time (LG and Samsung), TraceFree (ASUS), Rampage Response (ViewSonic), AMA (BenQ), or similar. Some monitors won’t have this setting, in which case you won’t be able to increase response time. Experiment with turning your response rate up (if you find the setting) while running the Blur Busters UFO Ghosting Test to see if you notice ghosting becoming more pronounced.
You should also be wary of other settings including noise reduction and dynamic contrast, or, if you’re using a TV, motion smoothing. These can all contribute to unwanted artifacts and ghosting.
Beware Pixel Overshoot When Using Overdrive
Unfortunately, monitor overdrive isn’t a perfect fix. The setting usually comes in a range of “strengths” or speeds, like a scale of one to five, or names like “fastest” or “extreme”. It may be tempting to turn this setting all the way up, but the main drawback to doing so is the introduction of pixel overshoot or coronas.
These unwanted artifacts occur as a result of the pixel going past (or “overshooting”) the desired color. Also known as inverse ghosting, the effect is caused by pixels transitioning too quickly and can result in a similarly distracting effect. Which setting you choose in terms of remedying ghosting with overdrive and avoiding pixel overshoot will depend largely on which monitor you’re using.
It also depends on your tastes. A small amount of ghosting may be more tolerable than the coronas caused by pixel overshoot. More often than not you’re going to want to settle on a “medium” overdrive setting to get the balance right.
Don’t Confuse Ghosting With Blooming
Blooming is another undesirable visual phenomenon that you may have heard of. Whereas ghosting refers to problems at the pixel level caused by response times, blooming is caused by LED backlighting, especially on displays that use full-array local dimming.
If you want excellent response times and no blooming, consider investing in an OLED display (or a newer QD-OLED monitor).