Monitor Ghosting, Motion Blur & Overdrive Overshoot
Pixel response time (GtG), eye persistence (MPRT), overdrive tuning, and corona artifacts.
Monitor ghosting is a visual trailing artifact caused by slow liquid crystals struggling to transition to new colors quickly enough, while inverse ghosting (overshoot) is caused by excessive voltage that pushes crystals past their target shade.
Why It Matters
Misconfiguring your monitor's overdrive setting can severely degrade motion clarity. Setting overdrive too low creates dark smearing, while setting it too high creates distracting bright glowing halos behind moving objects.
What Users Should Look For
- Dark smearing or colored trails lagging behind high-contrast moving objects (ghosting)
- Bright, glowing white or inverted colored halos preceding or following moving objects (overshoot / corona)
- Severe black smearing on VA panels when dark objects move across dark gray backgrounds
- Loss of text readability when scrolling quickly through documents or web pages
How to Test This Parameter
- 1Launch the Ghosting Test in Screen Tester to watch calibrated blocks move across high-contrast backgrounds
- 2Switch between low, medium, and high velocity to inspect trail persistence
- 3Open your monitor OSD menu and toggle through your monitor's Overdrive / Response Time settings (e.g., Off, Normal, Fast, Extreme) to find the optimal balance with zero overshoot
Technical Testing Boundaries & Methodology
Screen Tester emphasizes transparency: we clearly delineate between what web browser engines can mathematically inspect versus what requires specialized physical laboratory probes.
- ✓Rendering of high-velocity moving test blocks synchronized with display refresh intervals
- ✓Visual display of various color contrast pairings (e.g., dark gray on black vs. bright cyan on dark gray)
- ✓User visual tracking of trail length and halo intensity
- ✕Physical pixel transition times in milliseconds (Gray-to-Gray, GtG)
- ✕Moving Picture Response Time (MPRT) measured with a laboratory high-speed pursuit camera
- ✕Exact voltage waveforms delivered by the panel timing controller (T-Con)
GtG vs. MPRT: Two Different Types of Motion Blur
Gray-to-Gray (GtG) response time measures how long it takes a physical liquid crystal to rotate and change color (e.g., 1ms to 10ms). Slow GtG causes ghosting trails.
Moving Picture Response Time (MPRT) is caused by human eye tracking across a sample-and-hold display. Even if GtG was 0ms (as on an OLED), an image held on screen for 16.7ms (60Hz) smears on the human retina as your eye moves. Higher refresh rates (120Hz, 240Hz, 360Hz) or backlight strobing reduce MPRT.
Common Causes
- •Monitor Overdrive / Trace Free / AMA set to 'Extreme' or 'Ultra-Fast', inducing severe voltage overshoot
- •Monitor Overdrive disabled or set to 'Off', leaving slow liquid crystals with no voltage acceleration
- •VA panel architecture with inherently slow dark-level liquid crystal transitions (black smearing)
- •Monitor running at low ambient room temperatures, which physically slows liquid crystal viscosity
Recommended Next Steps
- →Open your monitor's on-screen display (OSD) and locate 'Overdrive', 'Response Time', or 'Trace Free'
- →Select the middle setting (typically 'Fast' or 'Normal'). Avoid 'Extreme' as it almost universally causes overshoot
- →Ensure your monitor is running at its maximum advertised refresh rate (e.g., 144Hz or 240Hz)
Frequently Asked Questions
What is inverse ghosting or 'coronas'?
Inverse ghosting (overshoot) occurs when a monitor over-accelerates liquid crystals using excessive voltage. Instead of settling at the target color, the crystal overshoots, creating a bright glowing halo that mirrors the moving object.
Can an OLED monitor suffer from ghosting?
OLED pixels transition in approximately 0.03 milliseconds, completely eliminating GtG ghosting. Any motion blur observed on an OLED is pure sample-and-hold eye tracking persistence (MPRT), solved by running at higher refresh rates.