The benefits of (non-perceived) flicker

Article: Lessons in Technology and Innovation from the iPad 3 Graphics and Display
By: Anon (no.delete@this.email.com), January 9, 2013 9:50 pm
Room: Moderated Discussions
Max (max.delete@this.a.com) on January 7, 2013 6:16 pm wrote:
> Ungo (a.delete@this.b.c.d.e) on January 7, 2013 3:57 pm wrote:
> > Max (max.delete@this.a.com) on January 7, 2013 1:43 pm wrote:
> > > Oddly enough the flickering nature of CRTs (whether perceived or not) makes them inherently superior
> > > in displaying motion than modern panel displays. A moving image (updated at the display refresh
> > > rate) appears sharp, whereas on a non-flickering display it appears fuzzy. This would be true
> > > even if the panel can update instantly, so it's not a problem that will ever go away.
> >
> > The bolded statement is not true. The reason why moving objects on LCDs often look fuzzy is because
> > LCD pixels have poor response times. Take that away, and the fuzziness should go too.
>
> That's a big problem, but even an absolutely perfect panel would have worse motion than a CRT.
>
> Think about how you're able to perceive a moving image as sharp. It's because the
> eye moves with the image, so the image is stationary with respect to the eye.
>
> When viewing a panel, the tracked image is only correct momentarily every frame. The rest of the time the image
> is wrong, and this wrong image is averaged by the eye with the correct image to produce a blurry image.
>
> You can see this effect with a CRT: take a 60Hz source and convert to 120Hz by repeating
> frames. The 120Hz version will be less sharp! (For motion that the eye can track).
>
> Max
>

Ah, no citations despite two polite requests other than more hand waving, time to (not surprisingly) call BS on this one I suspect.

It would seem that you are peddling some personal rationalisation of a want for a particular parameter to be maximised, marketeers love this in us, but it is very often wrong.

Also, you seem to completely misunderstand how we perceive motion, partially because you think eyes track a moving item on a frame by frame basis (incorrect) and secondly because of your absolutely crazy assertion that a frame doubled 60Hz sequence will be somehow less sharp (hint: it is exactly the same as a 60Hz version on a persistent display).

As an interesting experiment I set up a test for some of the BS using fast bright LEDs which is a simple and interesting experiment for those who care about actual facts.

2 LEDs with matched intensity, one running at 50% duty cycle, one at 100% (full on) but at reduced current to match intensity. Randomly assign which is which to make double-blind, and get people to guess with 1 second of illumination which is more steady.

In our office of 25 people, the average was just over 25Hz with any statistical relevance, and 2 people were exceptions at close to 50 - I asked them if they had any idea why and both stated (no surprise) that they intentionally looked away so the LED was in their peripheral vision (they knew the 'trick')

The implication is that 'most' are not able to detect a strongly changing signal at much over 25Hz visually in the center of vision, or 50Hz at the edges - funny how those figures match almost exactly who real systems are designed ;)

On the motion tracking BS, you may want to investigate the different between pursuit movement and saccades, and note that you would have to transition to the second for what you describe to happen, and while this can happen, it is unlikely below 20+ degrees/second of movement, which is I strongly suspect not what you are trying to describe (if you do want to experience this, tracking a fast moving car or aircraft going across your visual field is a good one, jet fighter displays are very common examples where the low aircraft appears to move in fast/slow jumps..).

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TopicPosted ByDate
Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayDavid Kanter2013/01/01 04:14 AM
  Games at 2048 x 1536? Can you tell?Mark Roulo2013/01/01 02:22 PM
    Games at 2048 x 1536? Can you tell?David Kanter2013/01/01 07:58 PM
      Games at 2048 x 1536? Can you tell?Anon2013/01/03 12:04 AM
        Games at 2048 x 1536? Can you tell?Andy2013/01/03 04:05 AM
          Games at 2048 x 1536? Can you tell?Anon2013/01/06 02:10 AM
            Games at 2048 x 1536? Can you tell?EBFE2013/01/06 11:07 PM
    Games at 2048 x 1536? Can you tell?Seni2013/01/01 09:17 PM
    Games at 2048 x 1536? Can you tell?anon2013/01/02 04:00 AM
      Games at 2048 x 1536? Can you tell?EduardoS2013/01/02 09:07 AM
        Games at 2048 x 1536? Can you tell?anon2013/01/03 12:21 AM
          Games at 2048 x 1536? Can you tell?EduardoS2013/01/03 01:03 AM
      Games at 2048 x 1536? Can you tell?Ricardo B2013/01/02 11:01 AM
        Games at 2048 x 1536? Can you tell?Michael S2013/01/03 01:35 AM
          Games at 2048 x 1536? Can you tell?Andy2013/01/03 04:10 AM
            Games at 2048 x 1536? Can you tell?Michael S2013/01/03 06:33 AM
              Games at 2048 x 1536? Can you tell?rwessel2013/01/03 11:56 AM
                Games at 2048 x 1536? Can you tell?rwessel2013/01/03 11:56 AM
                  Oh, for crying out load, would you fix this stupid thing to make it a tiny bit harder to double post (NT)rwessel2013/01/03 12:01 PM
                    /load/loud/ grrr... (NT)rwessel2013/01/03 12:02 PM
                    Oh, for crying out load, would you fix this stupid thing to make it a tiny bit harder to double postDavid Kanter2013/01/10 10:07 AM
                      Oh, for crying out load, would you fix this stupid thing to make it a tiny bit harder to double postrwessel2013/01/10 09:33 PM
                        Oh, for crying out load, would you fix this stupid thing to make it a tiny bit harder to double postrwessel2013/01/10 09:35 PM
                          Oh, for crying out load, would you fix this stupid thing to make it a tiny bit harder to double postrwessel2013/01/10 09:40 PM
                          Me, too! :-)Mark Roulo2013/01/11 08:57 AM
              85 Hz CRT monitorsDoug S2013/01/04 02:12 PM
                85 Hz CRT monitorsAnon2013/01/06 02:16 AM
                  85 Hz CRT monitorsDoug S2013/01/06 12:40 PM
                    The benefits of (non-perceived) flickerMax2013/01/07 01:43 PM
                      The benefits of (non-perceived) flickerAnon2013/01/07 02:59 PM
                        The benefits of (non-perceived) flickerPaul2013/01/07 05:40 PM
                      The benefits of (non-perceived) flickerUngo2013/01/07 03:57 PM
                        The benefits of (non-perceived) flickerDoug S2013/01/07 04:40 PM
                        The benefits of (non-perceived) flickerMax2013/01/07 06:16 PM
                          The benefits of (non-perceived) flickerAnon2013/01/09 09:50 PM
                            The benefits of (non-perceived) flickerMax2013/01/10 06:18 AM
                              The benefits of (non-perceived) flickerSM2013/01/10 12:37 PM
                        The benefits of (non-perceived) flickerdmsc2013/01/07 07:36 PM
                          The benefits of (non-perceived) flickerEBFE2013/01/07 11:08 PM
                          The benefits of (non-perceived) flickerAnon2013/01/09 10:07 PM
                            The benefits of (non-perceived) flickerdmsc2013/01/10 04:41 PM
                              The benefits of (non-perceived) flickerUngo2013/01/11 05:20 PM
                    perception of flickerCarlie Coats2013/01/08 04:39 PM
                      perception of flickerDoug S2013/01/08 10:25 PM
                        perception of flickerAnon2013/01/09 10:09 PM
        Games at 2048 x 1536? Can you tell?anongamer2013/01/03 04:31 AM
      Games at 2048 x 1536? Can you tell?Richard Cownie2013/01/02 02:56 PM
        Tablet vs. console GPUsDoug S2013/01/02 04:09 PM
          Tablet vs. console GPUsRicardo B2013/01/02 04:50 PM
      Games at 2048 x 1536? Can you tell?Anon2013/01/03 12:13 AM
        Games at 2048 x 1536? Can you tell?anon2013/01/03 12:54 AM
          The Hobbit is at 48 fpsRichard Cownie2013/01/03 07:02 AM
            Thanks for the interesting data point! (NT)Paul A. Clayton2013/01/03 09:26 AM
            The Hobbit is at 48 fpsRicardo B2013/01/03 11:17 AM
              The Hobbit is at 48 fpsRichard Cownie2013/01/03 11:55 AM
                The Hobbit is at 48 fpsRichard Cownie2013/01/03 12:44 PM
                  The Hobbit is at 48 fpsRicardo B2013/01/03 01:42 PM
                    The Hobbit is at 48 fpsRichard Cownie2013/01/03 02:31 PM
                      The Hobbit is at 48 fpsy2013/01/04 07:47 PM
                        Exposure time traditionsNathan Monson2013/01/05 12:21 PM
                          Exposure time traditionsy2013/01/05 09:59 PM
                            Exposure time traditionsanon2013/01/06 01:46 AM
                              Exposure time traditionsJukka Larja2013/01/07 08:52 AM
                            Exposure time traditionsdmsc2013/01/06 09:34 AM
                              Exposure time traditionsy2013/01/06 09:11 PM
                                Exposure time traditionsdmsc2013/01/07 07:42 PM
                                  Exposure time traditionsRichard Cownie2013/01/09 08:23 AM
                        The Hobbit is at 48 fpsMichael S2013/01/05 12:30 PM
                          The Hobbit is at 48 fpsRichard Cownie2013/01/05 03:45 PM
                            The Hobbit is at 48 fpsAnon2013/01/06 02:03 AM
                              The Hobbit is at 48 fpsRichard Cownie2013/01/06 06:43 AM
                                The Hobbit is at 48 fpsJukka Larja2013/01/07 09:18 AM
                                  The Hobbit is at 48 fpsRichard Cownie2013/01/07 05:21 PM
                                    The Hobbit is at 48 fpsJukka Larja2013/01/08 09:29 AM
                                      The Master 65mm/70mmRichard Cownie2013/01/08 12:52 PM
                                        The Master 65mm/70mmJukka Larja2013/01/11 02:07 PM
                                          The Master 65mm/70mmRichard Cownie2013/01/11 07:05 PM
                                            The Master 65mm/70mmJukka Larja2013/01/11 11:35 PM
                                              The Master 65mm/70mmDoug S2013/01/12 02:16 PM
                                                Pixar and 3DRichard Cownie2013/01/13 07:07 AM
                                            The Master 65mm/70mmDavid Hess2013/01/12 02:06 PM
                                            The Master 65mm/70mmMegol2013/01/16 01:02 PM
                                        The Master 65mm/70mmRakesh Malik2013/01/23 12:28 PM
                                    The Hobbit is at 48 fpsAnon2013/01/09 10:18 PM
                                      The Hobbit is at 48 fpsRichard Cownie2013/01/10 01:07 PM
                                        The Hobbit is at 48 fpsAnon2013/01/10 03:50 PM
                                          The Hobbit is at 48 fpsRichard Cownie2013/01/10 06:05 PM
                                            The Hobbit is at 48 fpsAnon2013/01/13 12:48 AM
                                              I don't care about workflowRichard Cownie2013/01/13 06:55 AM
                                                I don't care about workflowAnon2013/01/13 04:15 PM
                                                  I don't care about workflowRichard Cownie2013/01/13 08:02 PM
                                            The Hobbit is at 48 fpsRakesh Malik2013/01/23 01:38 PM
                              The Hobbit is at 48 fpsRakesh Malik2013/01/23 12:15 PM
                  The Hobbit is at 48 fpsJukka Larja2013/01/05 07:00 AM
                    Realism and fiction?Paul A. Clayton2013/01/05 09:42 AM
                      Realism and fiction?Jukka Larja2013/01/06 02:32 AM
                        Or the second factor?Paul A. Clayton2013/01/06 04:35 AM
                          Or the second factor?Jukka Larja2013/01/07 09:07 AM
                        further reading (was: Realism and fiction?)hobold2013/01/06 04:47 PM
                          Thanks. I'll probably check that out soon. (NT)Jukka Larja2013/01/07 09:13 AM
            The Hobbit is at 48 fpsrwessel2013/01/03 09:57 PM
            VR and latencyCarlie Coats2013/01/04 05:30 PM
              VR and latencyRicardo B2013/01/04 07:49 PM
                VR and latencyJoe2013/01/05 02:01 AM
            The Hobbit is at 48 fpsBernd Schmidt2013/01/08 03:42 AM
        Games at 2048 x 1536? Can you tell?anongamer2013/01/03 05:01 AM
        Games at 2048 x 1536? Can you tell?Ricardo B2013/01/03 08:06 AM
    Games at 2048 x 1536? Can you tell?Marco Salvi2013/01/02 10:31 AM
    Games at 2048 x 1536? Can you tell?Ungo2013/01/02 04:28 PM
    Games at 2048 x 1536? Can you tell?Jukka Larja2013/01/05 07:13 AM
  Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayRichard Cownie2013/01/02 10:29 AM
  iPad GPU Clock Speedsltcommander.data2013/01/05 12:32 PM
    iPad GPU Clock SpeedsBrett2013/01/06 11:48 PM
      iPad GPU Clock SpeedsDoug S2013/01/07 10:17 AM
      iPad GPU Clock SpeedsDavid Kanter2013/01/09 01:48 PM
    iPad GPU Clock SpeedsUngo2013/01/07 04:26 PM
      iPad GPU Clock SpeedsDavid Kanter2013/01/09 01:42 PM
  Lessons in Technology and Innovation from the iPad 3 Graphics and Displaympx2013/01/06 05:35 AM
    Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayMegol2013/01/07 04:45 AM
      Lessons in Technology and Innovation from the iPad 3 Graphics and Displaympx2013/01/07 12:56 PM
        Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayDoug S2013/01/07 04:53 PM
        Lessons in Technology and Innovation from the iPad 3 Graphics and Displayanon2013/01/07 06:26 PM
      Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayMaynard Handley2013/02/13 12:19 PM
  Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayVincent Diepeveen2013/01/06 03:29 PM
    Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayDoug S2013/01/07 10:53 AM
      Lessons in Technology and Innovation from the iPad 3 Graphics and Displaympx2013/01/07 12:48 PM
      Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayVincent Diepeveen2013/01/08 09:53 AM
        Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayDoug S2013/01/08 01:29 PM
          Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayLlew2013/01/26 12:06 PM
            Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayDavid Kanter2013/01/26 01:43 PM
              Lessons in Technology and Innovation from the iPad 3 Graphics and DisplayLlew2013/01/26 02:09 PM
            Wii U has three cores clocked at about 1.2 ghz or so. (NT)I.S.T.2013/01/29 07:37 PM
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