Visual MPRT & Persistence Test
Visual inspection pattern featuring fine alternating vertical slits and high-frequency grating. Illustrates the difference between pixel response time (GtG) and display frame hold time (MPRT).
- Track the moving vertical line grating continuously across the screen.
- Notice how the width of the blur trail corresponds to the duration each frame is held on screen.
- If your monitor features Backlight Strobing (ULMB, DyAc, ELMB, PureXP), toggle it in your monitor OSD to observe instantaneous persistence reduction.
MPRT (Moving Picture Response Time) represents the total duration that a single frame remains visible on your retina. While GtG (Gray to Gray) measures how fast liquid crystals physically rotate, MPRT dictates perceived motion blur. A 60Hz display has a baseline 16.7ms MPRT, a 120Hz display has 8.3ms, and a 240Hz display has 4.16ms. Backlight strobing (e.g. ULMB, DyAc) momentarily pulses the backlight off during frame hold time to achieve sub-1ms visual persistence.
What This Test Checks
- Visual persistence and moving slit grating clarity across your display.
- The fundamental difference between GtG (pixel transition time) and MPRT (frame hold time).
- Effectiveness of monitor backlight strobing modes (ULMB, DyAc, ELMB, PureXP).
- Perceived slit width expansion caused by retina eye-tracking smear.
How to Perform the Test
- Fix your gaze on the moving high-contrast vertical slits as they scroll across the screen.
- Notice how thin 2-pixel white slits appear to expand into wider blurred bars as you track them.
- If your monitor has a physical blur reduction or backlight strobing switch, turn it on in the OSD.
- Observe the immediate transformation from smeared bars back into razor-sharp, paper-like individual slits.
What to Look For
- Slit widening: On a 60Hz non-strobed display, slits widen significantly into solid white bands.
- Strobing clarity: With backlight strobing active, slits remain distinct individual lines even at high speeds.
- Crosstalk / Double Strobe: If strobing phase is misaligned, faint ghost duplicates will appear next to the slits.
Common Display Problems & Diagnostic Guidance
What is Strobe Crosstalk?
Strobe crosstalk occurs when the backlight pulses while liquid crystal pixels are still in the middle of transitioning states, resulting in a distinct double-image ghost at the top or bottom of the screen.
GtG vs MPRT: Why 1ms GtG Does Not Mean Zero Blur
GtG (Gray to Gray) measures only the transition speed of liquid crystals. MPRT (Moving Picture Response Time) measures the entire duration the pixel emits light to your eye. A 1ms GtG monitor running at 60Hz still has 16.7ms of MPRT blur.
Frequently Asked Questions
Can web browsers accurately measure MPRT in exact milliseconds?
No. Accurate millisecond MPRT measurements require external high-speed pursuit cameras or photodiode oscilloscopes. ScreenCheck provides honest visual persistence inspection patterns without generating fabricated numbers.
Why does backlight strobing make the monitor dimmer?
Because strobing turns the backlight completely off for the majority of each frame interval (e.g. on for 1ms, off for 7ms at 120Hz), overall light output to the room is reduced.