First, let me humbly apologize to the OP for bringing this thread off-track. However, I do want to bring something into correct record, though.
Originally Posted by Quic K Bunnie
I'm sorry, but there are some fundamental inaccuracies in your post. Pixel response is the cause of blur. Despite LCDs quoting gray-gray pixel transitions of less than 2 millisec, high speed digital photography clearly shows that on some LCDs, pixels cannot completely do transition even as fast as 1/30 sec (33 msec), showing up to 3 frames simultaneously. Scanning the backlight can improve the situation by illuminating less of the transition
1. LCD pixel response speed used to be the main cause of blur when LCD pixel response exceeded half the length of a frame. But 2ms is less than 20% of an LCD refresh cycle at 60Hz. The REMAINING (14ms out of 1/60sec) motion blur is CAUSED by eye tracking motion, smearing the already-refreshed LCD image across your retinas while you're tracking moving objects.True, confirmed academic FACT
: On today's modern LCD's _Most_ motion blur is now caused by eye motion while tracking a moving object on an LCD.
2. See academic citations
-- This academic paper
explains the difference between LCD pixel response and eye tracking blur, and they can actually be independent
variables. See the diagram on page 3. And shows how it is possible to 'bust' the LCD pixel refresh barrier, because many LCD panels today already practically finish refresh the frame by the end of their frame refresh cycle. See more citations
-- I can provide more, if desired.EXAMPLE: How an ultra-short-strobe scanning backlight can bust the LCD pixel response barrier (for the human eye)
Example of one 16.666ms refresh at 60Hz (1/60 = ~16.666ms)
T+0ms = LCD monitor begins refreshing pixel (unseen in the dark
T+2.4ms = Average LCD pixel response (Samsung SyncMaster SA950 example) (unseen in the dark
T+2.4ms = Approximate start of pixel ripple/bounce (e.g. response-time-compensation error recovery) (unseen in the dark
T+15ms = Slowest grey-to-grey transitions are finished (unseen in the dark
T+15.5ms = Strobe the backlight very brightly for only 1ms or 0.5ms (say, 1/960 or 1/1920 second) (seen by human eye
T+16.666ms = Next LCD monitor pixel refresh begins (unseen in the dark
) (and the cycle repeats)Voilà - Pixel response no longer the motion-blur barrier
For this example, your eye only sees a 0.5ms strobe of the finished LCD refresh. Your eyes DO NOT see the slow 2.4+ms LCD pixel response.
Persistence of vision and flicker fusion, just like for CRT, sees it as a solid image, despite the flicker. Given a sufficiently high refresh rate (72Hz, 85Hz, even 120Hz), the flicker is not noticed by most humans except the flicker-sensitive ones. The example applies to both scanning backlights (single strobe per refresh per backlight segment) and full black frame insertion (single full backlight strobe for full screen) -- equivalent effect. However, many LCD's take a finite time to begin refreshing the top and they gradually refresh, one pixel row at a time, towards the bottom, so scanning the backlights works best for that method of LCD controller behavior.
Scanning backights using ultrashort strobes (requires 10-20x brighter flashes to compensate for long dark periods) are not yet on the market, but vision tests and academic papers prove it is possible, and a few professionals in the display industry has agreed it is possible, given the right backlight and sufficiently bright flashes (at least as bright as a CRT phosphor -- they're really bright for that short time period before phosphor decay). So as you can see, today's LCD's have to finish refreshing pixels well before the end of the refresh, in order for them to be compatible with 3D, otherwise the images bleed to the other eye. This situation permits the design of ultra-short strobes of a duration that is shorter than the LCD refresh -- you just simply strobe at a different period in the timeline of a single refresh cycle.
With a high speed camera, an LCD with a ultrashort-strobe scanning backlight (90%:10% dark:bright), looks just like a scanning CRT, such as in this Youtube video
Thus, LCD pixel response is no longer the primary cause
of most of the motion blur on today's LCD anymore. Most of the motion blur is being caused by eye motion tracking a moving object across an LCD. Each frame is static for a whopping 16.6ms (at 60Hz) on a continuously-lit LCD, and your eyes is in motion during this period. I can give you some more citations
(click), and find even more, if you'd like.About PS Vita:
Note: I'm talking about full size displays. The PS Vita is wonderful, especially when dimmed, have very short OLED pixel pulses, so that eliminates quite a lot of motion blur. The pixels on it is not as fast as CRT phosphor decay, but at small sizes, you don't need CRT speed, because eye tracking blur is very small on small displays -- not much distance for eyes to track. So motion blur on handheld OLED is generally a non-issue -- It's a really very good OLED display, but I was originally talking about full size displays, which is a lot more challenging, as they need to be much brighter than a portable display, thus requiring longer OLED strobes, creating more opportunity for eye-tracking-based motion blur.About OLED
You're right in it's possible that they've solved the problem after years of delays/trying with OLED. I'm not saying it can't be done with OLED's, but the early OLED's have had so much problems when run at high brightnesses. It's possible that they may have solved the short-pixel-strobe problem. So *that* part, I *can* be proven wrong. Also, it takes very certain material to see motion blur at higher extremes (1) framerate equalling refresh rate; (2) fast pans in wide field of view (big displays), and (3) individual frames don't have blur in them (e.g. 3D games without GPU motion blur effects; or video taken by camera with fast shutter speed) .... So many people don't know how to detect for the "limits" of motion blur. However, my comment is correct: on modern LCD displays, most motion blur is caused by eye tracking, and not by the pixel response.
So will let this thread get back on topic. For discussion regarding the LCD pixel response no longer being the motion blur barrier, further discussion can be transferred to this other AVSFORUM thread
. Again, my apologies to the OP!