iPad Pro iPad Pro motion blur

Discussion in 'iPad' started by colinw123, Nov 16, 2015.

  1. colinw123 macrumors member

    Joined:
    Jan 21, 2013
    #1
    Hi, Just got my iPad Pro last Thursday, very impressed with the screen quality, nice and even screen, no yellowing, no backlight bleed etc. Am slowly getting used to the size of it but the only niggle for me is the motion blur is very noticable when scrolling, i normally just use it in landscape mode, but it does it both ways anyway.

    Just wondered if anyone else is sseing this as well.


    Thanks.
     
  2. sjleworthy macrumors 65816

    sjleworthy

    Joined:
    Dec 5, 2008
    Location:
    Penarth, Wales, UK
  3. colinw123 thread starter macrumors member

    Joined:
    Jan 21, 2013
  4. OCDMacGeek macrumors 6502a

    OCDMacGeek

    Joined:
    Jul 19, 2007
    #4
    I asked about this question a few days ago, as I felt the same way. I was told that the screen is 60 Hz, and that perhaps the larger screen exposes this issue more than we are used to on the smaller iPhone and iPad Air screens...
     
  5. colinw123 thread starter macrumors member

    Joined:
    Jan 21, 2013
    #5
    thanks for the reply, yes you maybe right, as the motion blur is hardly visible on my iPad 4, it's there but only slight, and not visible on my iPhone as it's soo small.
     
  6. highdefjunkie macrumors 6502

    highdefjunkie

    Joined:
    Apr 12, 2010
    Location:
    Chicago
    #6
    I honestly have noticed this as well. Hoping my eyes adjust and gets use to it.
     
  7. Atomic Walrus, Nov 16, 2015
    Last edited: Nov 16, 2015

    Atomic Walrus macrumors 6502a

    Joined:
    Sep 24, 2012
    #7
    I think I was the one who mentioned it being related to size. The motion blur is more visible when the object moves a larger distance on your retina, so a larger screen close to your eyes will display more motion blur.

    Your eyes can't really adjust to it, but I suppose you can get used to it. Sample and hold motion blur is just a property of LCD panels. Technically it's a caused by your brain and eyes (the screen doesn't actually turn blurry when things are in motion, that's just how we perceive it). There's an interesting trick you can do to confirm this: Keep your eyes locked on the static part of the screen while something moves. The moving object won't blur unless you start tracking it.

    Probably about to become way too much info, but here's what you optimally want to see when something moves (time on horizontal, position on vertical). This would be a continuous motion with no individual frames.
    Code:
    \
     \
      \
    Note that I couldn't make it to the same horizontal scale as the others because the \ is too steep, but it should be a more gradual slope to match the other diagrams.

    Here's what you see on a sample and hold (LCD) panel:

    Code:
    ____
        ____
            ____
    The image stays on screen until the next image is ready and replaces it. It creates a stair-step pattern that confuses your brain's motion tracking (the ball was stationary for 16ms, then it jumped to the next position, your eyes fail to track the motion and it looks blurry).

    If you were using a CRT you'd see this instead (we call this impulse):
    Code:
    _
        _
            _
    What happens here is that the image is flashed once, the screen goes dark for the rest of the frame time, and then it flashes again. From the diagram you can see that this time you have a straight diagonal line which is more like the "real world" example than the stair-step pattern. If the impulse rate is matched to the frame rendering rate then this will produce very low motion blur.

    In this situation the "ball" is still jumping from place to place, but it's no longer breaking the laws of physics from your perspective by teleporting. It's completely off screen for the time it would take to travel the distance, so your eyes can continue to track where they THINK it should be. When it reappears it will be exactly where you expected it to be, as though you're watching the moving object through a series of vertical fence posts.

    The problem with the CRT technique is that flickering displays, especially at a rate as slow as 60hz, cause tons of eye strain. Apple actualy goes out of their way to not even use PWM (high freqency flicker) dimming for its LCDs because even those higher frequencies can cause eye strain. When you have an impulse display the individual exposures have to be much brighter to create the illusion of an even, moderate brightness, and whether you can see it or not many people report this irritating their eyes over long periods of use.

    If you're math-oriented you can see that what we want is a continuous function which has a defined, non-zero derivative everywhere (or as close as possible since that's not something you can actually achieve). The derivative dy/dt is the time rate of change of the position of the object, and for smooth motion this value should never be zero or "infinity" because this means the object will appear to be stopping and then jumping instantly to a new position.

    The optimal solution is not impulse drive, it's simply more frames per second. Managed to build something close to what I mean as a comparison to diagram 2.
    Code:
    --__
        --__
            --__
    The motion blur length is determined by the time each frame remains on screen. That's 16ms for a 60hz display, but go to 120hz and it gets cut in half. If you ever try a 120hz monitor (don't be confused by "120hz" TVs) on a computer that can handle the 120hz output and rendering 120 frames per second you'll see that motion blur is significantly reduced, to the point where you can clearly read text that's scrolling fairly quickly. Of course current monitor tech means that you have to trade color accuracy for increased refresh rate (and the GPU/CPU work harder to produce twice as may frames).

    TL;DR
    It's a motion perception issue with display tech, nothing anyone can easily solve today, looks worse when the screen is taking up more of your vision, I clearly have too much time for writing long forum posts.
     
  8. thisisnotmyname macrumors 65816

    thisisnotmyname

    Joined:
    Oct 22, 2014
    Location:
    known but velocity indeterminate
    #8
    @Atomic Walrus - thank you, I've really appreciated a couple of the deep technical explanations you've given recently (the other being latency of the pencil).
     
  9. OCDMacGeek macrumors 6502a

    OCDMacGeek

    Joined:
    Jul 19, 2007
    #9
    Thanks for the explanation. It does seem like perhaps this is an issue with all iPad Pros based on the technology, but given how I am aware of the phenomenon and never saw it even on the iPad Air, I feel uncertain that the issue is the same. While I have witnessed motion blur on many television screens, this is the first time I am really seeing it on any Apple device -- Mac or iOS. Part of the problem, of course, is that since it is so subjective it will be difficult to determine if other users have devices that do not have this problem, or if they just can't see it. I can't help wondering if there were multiple screens suppliers, and perhaps some screens are worse than others. However, I am going to just try and ignore this and enjoy the device!
     
  10. WilliamG macrumors 604

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #10
    I've absolutely experienced the same "issue" with the iPad Pro. I even pulled out my iPad Air 2 day one to compare because I thought the motion blur on the Pro felt excessive. But nope, it's just the larger size of the Pro screen accentuating the blur, sadly.

    Be nice to have a 120 or 240hz display, of course, but that would require a flawless UI frame rate which even at 60hz the iPad Pro doesn't have.
     
  11. OCDMacGeek macrumors 6502a

    OCDMacGeek

    Joined:
    Jul 19, 2007
    #11
    Oddly, it's nice to hear that it is at least not a defect specific to those of us who have noticed it, and that its just something all of us have no choice but to get used to.
     
  12. WilliamG macrumors 604

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #12
    Yep, glad to share the first-world-problems misery with you. :)
     
  13. colinw123 thread starter macrumors member

    Joined:
    Jan 21, 2013
    #13
    Atomic Walrus, wow thanks for the advanced info :)

    And thanks for all your other comments, good to know it's not just me seeing things.

    One interesting thing i have found is in a dimly lit room when the iPad brightness is very low the motion blur improves a lot. But during the day when the brightness is higher then its worse. I thought i was imagining this at first but have witnessed this on several evenings.

    anyway thanks again.
     
  14. pr0230 Suspended

    Joined:
    Feb 7, 2013
    #14
    Hello... Currently I have an iPad 4 I think... First year they came out with 128gb... Any way, I love the screen and watch a lot of youtube on it... The Retina display is Great. I was hoping the iPad pro would have an even better screen and resolution. From what I understand the PPI for the iPad PRO is no better than mine?
    The iPad PRO has the MOST pixels for ANY tablet surface or apple, but only because of the larger size...

    This blur issue is a show stopper for me, and maybe a good reason to wait for the NEXT version of the PRO... Hopefully a 4K or 5K version...
     
  15. WilliamG macrumors 604

    Joined:
    Mar 29, 2008
    Location:
    Seattle
    #15
    Higher resolution isn't going to solve this "issue." You own an LCD TV I'd guess. Go stand up close to and watch how motion behaves. It's the same as the Pro. It's just the nature of larger screens close to you.

    And yes, the ppi (and more importantly - sppi) is the same as your iPad Air.
     
  16. OSMac macrumors 65816

    Joined:
    Jun 14, 2010
    #16
    Noticed the scroll blur issue right away on the in store demo unit using safari.

    I'll sure it will improve in future generations. The screen may have a 60Hz refresh but it seems the frame rate drops when scrolling?
     
  17. farewelwilliams macrumors 65816

    Joined:
    Jun 18, 2014
    #17
    there's definitely some motion blur. running slomo on my iphone 6+:
    [​IMG]
     
  18. Viper2005 macrumors 6502

    Viper2005

    Joined:
    Dec 2, 2007
    Location:
    Canada
    #18
    I suspect Apple may have selected an LCD screen with a slower refresh rate as a power saving measure due to the size of the screen.
    The IpadPro is touted to have a variable refresh rate so it does not refresh as often when there is no motion on the screen, to save power. Though I'm not sure if this is what is causing the blurring issue.
     
  19. Branskins macrumors 65816

    Joined:
    Dec 8, 2008
    #19
    I've just started noticing this in Tweerbot. Not sure if it developed overnight or if it just caught my eye
     
  20. Deasnutz macrumors 6502

    Joined:
    Jun 9, 2011
    #20
    Where did you see info about variable refresh? This site has multiple tools to check framerate and motion blur:

    http://testufo.com/#test=framerates
     
  21. BrennerM macrumors regular

    Joined:
    Jun 17, 2010
    Location:
    Kitchener, Ontario, Canada
    #21
    When I first got my iPP I really noticed the motion blur, much more than on my iPad 3. But now I don't really notice it in general use unless I specifically focus on it.
     
  22. Branskins macrumors 65816

    Joined:
    Dec 8, 2008
    #22
    This website is very cool! Thank you
     
  23. thadoggfather macrumors 604

    thadoggfather

    Joined:
    Oct 1, 2007
    #23
    I think it has to do with the refresh rate spec of panels they're using.

    My iPP I tried out had it. Screen was also jaundice.
     
  24. Pug72 macrumors 6502a

    Pug72

    Joined:
    Mar 18, 2012
    Location:
    England
    #24
    Has been the same on all my iPads in the past too.
    The larger screen does emphasise it though I think.
     
  25. Jacquesd2 macrumors newbie

    Jacquesd2

    Joined:
    Feb 13, 2016

Share This Page