Blur Busters Forums

Anyone have any thoughts on how would one be able to achieve low persistance pixels without flickering the screen @ a fixed rate?

I realize it isnt possible with the tech we have now, but image that OLED with its 0.02ms response times is on the table.
Just curious, has anyone got any ideas on this? The goal is a theoretical flicker free, blur free, variable refresh rate display.

One idea is having your framerate almost 1000fps on a variable refresh 1000hz display. And you get almost 1ms persistance on a flicker free variable refresh display.

Any other ideas? Less fps demanding ones?

oled response time doesnt matter much

i think limitation is video bandwidth

you will be need both instant pixel transition and ultra high refresh rate, like a 1000Hz OLED VR panel.

lol37 wrote:you will be need both instant pixel transition and ultra high refresh rate, like a 1000Hz OLED VR panel.

I feel sad that you didnt even read my post.

there's no other ways to do like so. (Mark wrote an article about it around his website)
yet the OLED technology dramatically reduce pixel persistence, it'll look pretty good even at "only" 120fps@120hz

lol37 wrote:there's no other ways to do like so. (Mark wrote an article about it around his website)
yet the OLED technology dramatically reduce pixel persistence, it'll look pretty good even at "only" 120fps@120hz

Low-persistence OLED also flickers. The low-persistence rolling-scan OLEDs also flicker.

Normal flickerfree OLED is high persistence, even if GtG is fast. GtG in milliseconds, is not the same thing as persistence in milliseconds.

For simultaneously flicker-free AND blur-free, currently requires unobtainium refresh rates. Interpolation is one method of lowering persistence without using light modulation (aka flicker/strobing/pwm/phosphor cycling/etc).

Persistence is the frame(refresh) visibility time.
Higher framerate & refresh rate = shorter frame visibility time
Or if you use strobing:
Shorter strobes = shorter frame visibility time

60Hz flicker free = 1/60sec persistence = 16.7ms persistence
120Hz flicker free = 1/120sec persistence = 8.3ms persistence

To get the same persistence as a 1ms strobe backlight, but using a flickerfree method, you require 1000fps@1000Hz to achieve 1ms persistence via a flickerfree method, or 500fps@500Hz to achieve 2ms persistence via a flickerfree method.

Coming at this from an ideal perspective (i.e. ignoring current technical limitations), as I think OP wanted, there doesn't seem to be any escape from either having a high framerate or low framerate with strobed backlight and flicker. Our eyes need light more often than once every 1/60 second to not perceive flicker, and the only ways to provide it is either continuously or at a high rate of strobed frames. Within this context interpolation is a less-intensive way of increasing frame rate, though with inevitable artifacts.

what if you could just take some drug or hallucinogen that makes you less sensitive to flicker

blargg wrote:Coming at this from an ideal perspective (i.e. ignoring current technical limitations), as I think OP wanted, there doesn't seem to be any escape from either having a high framerate or low framerate with strobed backlight and flicker. Our eyes need light more often than once every 1/60 second to not perceive flicker, and the only ways to provide it is either continuously or at a high rate of strobed frames. Within this context interpolation is a less-intensive way of increasing frame rate, though with inevitable artifacts.

True. That's why strobe backlights often run at 120Hz. However, flicker is indirectly detectable via the stroboscopic effect well past 1,000Hz -- see So What Refresh Rate Do I Need? for the discussion of motion side effects that are still human-visible even at 1000Hz or 2000Hz. (including links to scientific studies/research). 1000Hz flicker is indirectly detectable by human eye via the stroboscopic effect (phantom array effects / dotted blurring / wagon wheel effects).

1000fps@1000Hz is a good goal, but it will still not be perfectly able to pass what I call the "Holodeck Turing Test" ...as in "Wow, I didn't know I was standing in a Holodeck and not real life" or more realistically, "Wow, I didn't know I was wearing virtual reality goggles instead of ordinary ski goggles!" 1000Hz flicker still has the strobe effect. And if you stopped strobing and used sample-and-hold, that's still not perfect either -- 1000Hz sample-and-hold still creates minor motion blur (1ms = 1 pixel of blurring during 1000 pixels/sec, so would result in 10 pixels of blurring during 10,000 pixels/sec during fast head-turning on 4K VR goggles).

BUT, 1000fps@1000Hz will still be startlingly close to real life -- and is still a holy grail.

For now, 120Hz+ rolling-scan OLEDs with ultrabright sub-millisecond persistence, is probably a more realistic "dream display" by the end of this decade. Whether as a VR display or a desktop display.

flood wrote:what if you could just take some drug or hallucinogen that makes you less sensitive to flicker

Unfortunately, even if you stop being sensitive to flicker, you still got the phantom-array effect (dotted/broken blur effect), and/or the wagonwheel effect to contend with. Not everyone notices this, though, much like not everyone notices the rainbow effect of DLP projectors.