Strobed Motion Blur Reduction Is Same As PWM (but good kind of PWM)
Posted: 27 Mar 2020, 20:23
Educational article, about people confused about PWM dimming versus motion blur reduction...
Properly Choosing Poisons In Pick Poison
PWM is usually bad. But sometimes some people have MORE headaches from motion blur (this was a big problem in VR until VR headsets started strobing). But this can still affect high-motion material, like scrolling / panning / turning, especially if you're eye tracking in nauseating motion blur. In this case, strobing (PWM backlight at ONE FLASH per frame only) becomes the "better of pick poison".
Did You Know? Motion Blur Reduction Strobe backlights are simply one-flash-per-refresh PWM. A "good kind of PWM".
First, to understand how PWM interacts with motion blur, see this simple diagram.
That's why unsynchronized PWM is so bad:
With PWM dimming, motion look serrated, creating eyestrain that is sometimes also unrelated to the PWM flicker. To some people, they are so sensitive, that it almost feels like a serrated knife that stabs the eyes. This is why PWM dimming is hated by many. However, single-strobe PWM (blur reduction PWM) has far less eyestrain than multi-strobe PWM (PWM dimming strobe).
That's why some people don't get eyestrain (or less strain) from blur reduction modes (at fps=Hz), but gets far more eyestrain from unsynchronized PWM dimming. Which is awful, and should not exist in a monitor.
Sure, we wish we could eliminate motion blur without PWM, but that currently requires higher frame rates at higher refresh rates. Sometimes even 240fps at 240Hz doesn't yet reduce enough motion blur (without strobing).
Some people still get eyestrain from both, but usually, blur-reduction PWM is far by the lesser of evil compared to multi-strobe PWM dimming. It's far worse than CRT 30fps @ 60Hz for some human eyes. Not everyone gets the same kind of eyestrain/fatigue from the same causes from the same display. Focus eyestrain. Motion sickness. Motion blur eyestrain. Brightness strain. Blue light. Color blindness. Etc. Everybody sees differently.
Finite-refresh-rate displays are inherently imperfect compromises, especially for some people sensitive to the artifacts that cannot be solved by most displays. You might be one of the 90%+ that is not bothered by this or that, but the other 10% or 1% are. That's one reason why some of us like strobe backlights modes (while others hate them). The imperfectness of displays is why Blur Busters continues to successfully exist.
References:
-- LCD Motion Artifacts 101
-- Blur Busters Law: The Amazing Journey To Future 1000Hz Monitors
(there's several flicker paragraphs halfway down. Please read this page carefully)
Properly Choosing Poisons In Pick Poison
PWM is usually bad. But sometimes some people have MORE headaches from motion blur (this was a big problem in VR until VR headsets started strobing). But this can still affect high-motion material, like scrolling / panning / turning, especially if you're eye tracking in nauseating motion blur. In this case, strobing (PWM backlight at ONE FLASH per frame only) becomes the "better of pick poison".
Did You Know? Motion Blur Reduction Strobe backlights are simply one-flash-per-refresh PWM. A "good kind of PWM".
First, to understand how PWM interacts with motion blur, see this simple diagram.
That's why unsynchronized PWM is so bad:
With PWM dimming, motion look serrated, creating eyestrain that is sometimes also unrelated to the PWM flicker. To some people, they are so sensitive, that it almost feels like a serrated knife that stabs the eyes. This is why PWM dimming is hated by many. However, single-strobe PWM (blur reduction PWM) has far less eyestrain than multi-strobe PWM (PWM dimming strobe).
That's why some people don't get eyestrain (or less strain) from blur reduction modes (at fps=Hz), but gets far more eyestrain from unsynchronized PWM dimming. Which is awful, and should not exist in a monitor.
Sure, we wish we could eliminate motion blur without PWM, but that currently requires higher frame rates at higher refresh rates. Sometimes even 240fps at 240Hz doesn't yet reduce enough motion blur (without strobing).
Some people still get eyestrain from both, but usually, blur-reduction PWM is far by the lesser of evil compared to multi-strobe PWM dimming. It's far worse than CRT 30fps @ 60Hz for some human eyes. Not everyone gets the same kind of eyestrain/fatigue from the same causes from the same display. Focus eyestrain. Motion sickness. Motion blur eyestrain. Brightness strain. Blue light. Color blindness. Etc. Everybody sees differently.
Finite-refresh-rate displays are inherently imperfect compromises, especially for some people sensitive to the artifacts that cannot be solved by most displays. You might be one of the 90%+ that is not bothered by this or that, but the other 10% or 1% are. That's one reason why some of us like strobe backlights modes (while others hate them). The imperfectness of displays is why Blur Busters continues to successfully exist.
References:
-- LCD Motion Artifacts 101
-- Blur Busters Law: The Amazing Journey To Future 1000Hz Monitors
(there's several flicker paragraphs halfway down. Please read this page carefully)