Blur Busters Forums

RealNC wrote:

Glide wrote:The whole screen is affected by a double-strobe, not just the moving object.

But only moving objects show up double. It's the reason why viewing a static photograph at 5FPS is perfectly smooth with no stutter

When you eye is moving to track an object moving across the screen, even static objects on the display are moving across your retina.
The entire display shows double-images caused by the double-strobe, not just the object in motion.

Glide wrote:When you eye is moving to track an object moving across the screen, even static objects on the display are moving across your retina.
The entire display shows double-images caused by the double-strobe, not just the object in motion.

Static objects will look exactly the same in that case in both single as well as double strobe since they have no frame rate. Static objects are 0FPS. The only difference will be the flicker, and you'll get less of it in double strobe.

Glide wrote:When you eye is moving to track an object moving across the screen, even static objects on the display are moving across your retina.
The entire display shows double-images caused by the double-strobe, not just the object in motion.

Actually, stationary stuff in the periphery (surrounding your moving eyes tracking an object) will still have a phantom array effect -- it still occurs even in single-strobe. That can appear as a multi-image effect -- not necessarily just two (double-image).

And in some cases, even when the display is not strobing.

A huge book can be written about vision phenomena on a display...

RealNC wrote:Static objects will look exactly the same in that case in both single as well as double strobe since they have no visible frame rate. Static objects are visually 0FPS regardless of their actual framerate.

Correct. (After FTFY).
Static objects have no visually measurable framerate, and any framerate looks exactly the same as 0fps.

Ya I only spent a minute on those pictures as I am quite busy lately. I'll try and post some better pics from my linear rail (arm) this weekend.

Chief Blur Buster wrote:*snip*

I know that if the persistence is higher the double image effect is not a thing(like in the case of 30fps@60hz with sample and hold) but I've been wondering lately if the reverse could also be true. Like if the persistence is completely zero(well more like something in the micro/nanoseconds since 0 is practically impossible) maybe the double image effect completely vanishes in that case too since it should be quick enough to flash 2(or more) of the same image instantaneously enough for the human eye/brain not to perceive it, though this is just me brainstorming

Also, I know that at 60fps@85hz the double-image effect is less severe. I wonder if this OLED can somehow strobe internally at 85hz(instead of the 120hz it's doing right now)

No, the double flash would still be visible. The only way to remove it would be with some kind of extrapolation, like various time warp techniques in VR headsets.

With 60fps@85hz you'd get either severe tearing or judder, so that's a no-no.

Also, if you get too low with the persistence, then you see only black. There's a lower limit on the amount of light the brain registers. It detects it (the eyes and brain can detect even a single photon, which amazed me when I first learned about it), but it then filters it out ("anti-noise" mechanism) and we can't consciously perceive it.

RealNC wrote:Also, if you get too low with the persistence, then you see only black.

Not necessarily. That depends on the brightness output, currently we don't have bright enough displays to pull it off now but that may change in the future

Both of you are right -- under different variables

RealNC wrote:Also, if you get too low with the persistence, then you see only black.

If you don't increase brightness, that's correct. Eventually, there's too photons to register with human vision.

thatoneguy wrote:Not necessarily. That depends on the brightness output, currently we don't have bright enough displays to pull it off now but that may change in the future

Yes, if you double brightness (e.g. double the number of photons per microsecond) while halving strobe length, you can maintain brightness level.

For example -- human eyes can see a one-millionth-second flash -- but it has to be an insanely bright flash in an insanely short time period. 1000 times brighter than an equivalent millisecond flash, to be specific. Not possible to do with current monitor backlights, alas.

Some monitors can boost strobe backlights by about 3x brighter during their flashing. This is how LightBoost does it. Many LEDs can be overdriven harder without long-lasting effect, if they're flashed more briefly. But there's a limit.

Chief Blur Buster wrote: Yes, if you double brightness (e.g. double the number of photons per microsecond) while halving strobe length, you can maintain brightness level.

For example -- human eyes can see a one-millionth-second flash -- but it has to be an insanely bright flash in an insanely short time period. 1000 times brighter than an equivalent millisecond flash, to be specific. Not possible to do with current monitor backlights, alas.

Some monitors can boost strobe backlights by about 3x brighter during their flashing. This is how LightBoost does it. Many LEDs can be overdriven harder without long-lasting effect, if they're flashed more briefly. But there's a limit.

I wonder how many lumens would be necessary to get something like micro/nanosecond persistence(potentially eliminating double/-image effect at any refresh rate entirely that way)? Maybe millions which I'm not sure is possible, but it's fascinating to think about

Phosphors used to shine at 5000 lumens for a brief period and nowadays the highest lumens we have in any sort of display tech is 10000 lumens in Theatre Laser Projectors