Motion blur
Display motion blur is the smear you see when your eye follows a moving object on a screen that holds each frame lit for the whole refresh interval.
Also known as sample-and-hold blur, persistence blur, display motion blur
Not measurable from a browser
A web page cannot read this directly. The paragraphs below say what a page can and cannot see, and which tool or reading covers the rest.
An LCD or OLED without backlight strobing is a sample-and-hold display: each frame stays lit until the next one replaces it. Your eye tracks a moving object smoothly, but the image moves in steps, so during each frame the still image slides across your retina. The smear is about the distance the object travels in one frame.
That makes the core of it arithmetic. Blur in pixels is the frame time in milliseconds times the speed in pixels a second, divided by 1000. At 60 Hz an edge moving at 960 pixels a second smears about 16 px, and doubling the refresh rate halves it. Slow pixel response adds more blur and overdrive can add bright or dark trails, while backlight strobing and black frame insertion cut the persistence and with it the smear, at some cost in brightness.
Spec sheet figures do not agree on how to measure it. VESA's ClearMR certification rates a display by the ratio of clear to blurry pixels, in tiers from ClearMR 3000 to 9000, tested with backlight strobing off, and VESA states that it replaces MPRT and other methods of blur characterisation. A web page cannot measure blur on the panel; the motion tests show a moving pattern at a known speed so you can judge it by eye.
Covered in full
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