LCD Motion Artifacts: Overdrive

Originally Posted September 2013. Updated JUNE 2019

This article is part of the LCD Motion Artifacts 101 series. This page illustrates overdrive artifacts (inverse ghosting) of different response time acceleration settings on a computer monitor. Different manufacturers uses different terminology. ASUS uses “Trace Free” for their computer monitors, while BENQ uses “AMA“, and Acer uses “Overdrive“.

asus-tf0-ghosting

Ghosting Artifact (minimum overdrive)

asus-tf100-coronas

Corona Artifact (maximum overdrive)

The UFO ghosting test at www.testufo.com/ghosting is run at 960 pixels/second with a pursuit camera to create accurate photographs of different overdrive settings.

Recent Comparison Between Overdrive Settings

Older Comparison Between Overdrive Settings

Animation of Asus Trace Free settings 0, 20, 40, 60, 80 and 100

ASUS TraceFree 0: Ghosting is very visible, especially at the left edge of the UFO dome.tracefree0

ASUS TraceFree 20: Ghosting is still visible at the left edge of the UFO dome and base.tracefree20

ASUS TraceFree 40: Ghosting almost gone. Very faint white ghosting at base of UFO.tracefree40

ASUS TraceFree 60: Ghosting is now gone. Faint corona at left edge of UFO base.tracefree60

ASUS TraceFree 80: More visible corona at left edge of UFO base.tracefree80

ASUS TraceFree 100: Very visible corona at left edge of UFO base.tracefree100

Observation

It is observed there is a trade-off between ghosting and coronas:
1. Low overdrive settings can cause ghosting to appear.
2. High overdrive settings can cause coronas to appear.
For ASUS computer monitors with the “Trace Free” adjustment, an excellent compromise setting is usually Trace Free 60, which balances ghosting visibility with corona visibility.

Another method of reducing the visiblity of ghosting and coronas is to use a faster LCD display (e.g. 120Hz, 144Hz, or 240Hz monitor) and/or to use an LCD display with a strobe backlight such as ULMB or LightBoost (see Motion Blur Reduction FAQ) which hides pixel transitions by turning off the backlight between refreshes, as well as reducing motion blur (60Hz vs 120Hz vs ULMB). Ghosting and coronas are the visible pixel transitions being seen by the human eye.

Tested monitor: ASUS VG278H, running at 120Hz, using the test at www.testufo.com/ghosting running at 960 pixels/second. Different monitors and refresh rates can have different overdrive strengths. Artifacts may show up at lower or higher overdrive settings on another monitor. The motion artifacts are otherwise very similar.

What is Overdrive For?

Without overdrive, LCD displays are prone to ghosting. Ghosting is typically caused by the asymmetric speeds of pixel transitions. LCD pixels often transition faster (or more completely) to a specific color, than back from a specific color. This creates the differences in motion artifacts on the leading edge versus the trailing edge of moving on-screen objects.

Overdrive speeds up the pixel transitions by using higher voltages on the pixels. This reduce ghosting. However, excess overdrive can create coronas. Coronas, also known as “overdrive artifacts”, or “inverse ghosting”, is caused by the pixel overshooting its final color value, and rippling (bouncing back) to its final color value.

The use of overdrive can also reduce motion blur very slightly, but only up to the limitations of the sample-and-hold effect. See www.testufo.com/eyetracking for an animation that demonstrates display motion blur unrelated to speed of pixel transitions.

How Were These Images Captured?

Stationary Camera: Capture of Pixel Transitions

A stationary camera is good for photographing pixel transitions statically. However, it is not a very accurate representation of perceived display motion blur and motion artifacts:

stationarycam_persistence
Example: Stationary camera photo of a moving object on a display.

Pursuit Camera: Accurate Capture of LCD Motion Artifacts

Pursuit camera are used by display manufacturers for testing (e.g. MPRT pursuit cameras). This is simply a camera that follows on-screen motion. These expensive cameras are extremely accurate at measuring motion blur and other artifacts, since they simulate the eye tracking motion of moving eyes.

However, Blur Busters has developed an inexpensive pursuit camera method which operates in conjunction with the Blur Busters UFO Motion Tests. It makes possible accurate photography of motion artifacts. The test at www.testufo.com/ghosting was used to take the pictures on this page. Blur Busters is the world’s first blog to utilize a pursuit camera for accurate capture of motion artifacts, in WYSIWYG format, as seen by the human eye.

More Reading About Pixel Response

LCD motion artifacts are frequently caused by pixel response imperfections. For more information about pixel response, see GtG versus MPRT: Frequently Asked Questions About Pixel Response.


16 Comments For “LCD Motion Artifacts: Overdrive”

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WillH5080
Member
WillH5080

“Hello! Thank you for the article! I need help. I bought new monitor of ASUS VP28UQG and i have I tested it with pubg and the wither 3.
With OD off, no coronas but high blur or ghosting.
With OD normal, ghosting decreased very much but there is very slightly coronas, only seen on white sharpe edges on the open spaces if i focus on them.
With OD extreme, no ghosting but very high coronas.
Is this normal with IPS ?”

konto94
Member
konto94

Hello guys i need help i just buy new monitor of samsung https://www.samsung.com/at/monitors/27-zoll-curved-gaming-crg5/ and i have problem like the picture on top like the acer predator…my monitor specially on pubg is ghosting…and i don’t know how to fix..i try to set the game borderless seems like it fix it but it’s not so smooth like full screen..Guys please help me to fix it.Im waiting for a reply thanks!

hexaae
Member
elies
Member
elies

Hello. Thank u for your article.
Please i need your help.
I bought the XB271HU IPS GSYNC 144hz monitor.
I tested it with forza horizon 3.
With OD off, no coronas but high blur or ghosting.
With OD normal, ghosting decreased very much but there is very slightly coronas, only seen on white sharpe edges on the street if i focus on them.
With OD extreme, no ghosting but very high coronas.
Is this normal with IPS ?
I thought with OD normal, i can decrease ghosting with 0 coronas but coronas are there but very slightly and i can see it with ufo test.

jmcsmfpc
Member
jmcsmfpc

Does anyone know what monitor was used for the trace free test? and was it at 144hz?

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