6 ms·

Is being able to distinguish a single pixel the same thing as noticing that text is sharper? I've noticed that you can't stop doing subpixel font rendering on d

by pkulak 8y ago

Is being able to distinguish a single pixel the same thing as noticing that text is sharper? I've noticed that you can't stop doing subpixel font rendering on displays until they get far above a density that optometrists say shouldn't matter anymore.

ramraj07 8y ago
This. People always keep forgetting that our brain is definitely capable of some amount of superres lotion calculations especially for very specific types of structures. One aspect I've always been fascinated about is how far away someone can be when I can still tell that they're looking at me and not the person next to me. Most of the time I can definitely not read any text (even at 16 pts) if it was held at that distance but I can subconscuously tell the subtle differences in the angle their eyeballs are at. Same thing with 60fps vs 120fps. People keep saying you can tell them apart but I sure as well can at least in some instances.
- Paperweight 8y ago
  It's also annoying when they say you shouldn't be able to tell that PWM headlights/taillights are flickering but I sure as hell can, at least!
  - freyir 8y ago
    Yeah, and when they say Wi-Fi shouldn't make my brain tingle
    - tokyodude 8y ago
      you're being downvoted and I have no idea if it would actually be possible to be sensitive to wifi but I can hear my 2014 MacBook Pro process certain things and I don't mean the fan. No idea what triggers the processing "buzz" because it's not constant but certain cpu intensive operations make a buzz I can hear so I can certainly believe a similar buzz could come from a router's processor
      - Wowfunhappy 8y ago
        That's called coil whine! It could happen in a router, but it seems unlikely in such a low power device.
        antsar 8y ago
        I’ve used a 5-port ethernet switch (even lower power than a router) with very substantial coil whine. Like, “can’t tolerate it without headphones” substantial.
        leoleoleoleo 8y ago
        Tplink sg105e by any chance? I can hear mine from 3 meters away.
        antsar 8y ago
        Just checked. That's exactly the one.
        AngryData 8y ago
        My graphics card had it terrible, well atleast until it died a two weeks ago. But it most often made the noise at an audible frequency during low power usage. When it got hit hard it stopped being a problem, but it could have just been pushing it outside of my audible range.
  - monochromatic 8y ago
    Definitely noticeable when my eyes are moving quickly, glancing from one location to another.
    - Paperweight 8y ago
      Like when you're driving? :)
  - btgeekboy 8y ago
    LED Christmas lights are the worst at this. I can definitely see the 60hz flicker, especially if there's movement.
- cryptonector 8y ago
  FPS matters a great deal in video games -- 120 is fantastically better than 30. FPS really doesn't matter that much in movies, much less TV shows, even action movies.
- npunt 8y ago
  Eyes can definitely tell more than 60hz, especially the rods in your peripheral vision. From what I remember in cog sci classes it was about 72hz that was just noticeable difference (JND), but I think this may be a bit higher in rods, and have small difference by gender. One way to tell is look at a CRT off-angle and adjust refresh rates until its no longer perceptible. Angle of eyes may be different and I'm more skeptical of whether we can tell if people really are looking at us off-angle or from considerable distance. On the one hand, we're certainly hyperaware of faces both in central and peripheral vision, as part of our brain is dedicated to face detection, and eyes have high contrast (black on white). And looking dead-on at someone's eyes we can infer where they're looking even from pretty far away. All of this of course serves a social / evolutionary / survival purpose. On the other, it may be that peripherally all we can tell that someone's is facing us and has open eyes, and this leads us to have a premonition that someone is looking at us. When we look up to confirm, this may or may not be true, but we'd be more likely to remember/encode that they were, thus making that sense err on the side of assuming people are looking at us. Add to that our own sudden shift in the angle of our face/eyes, which may cause them to react and look our way. We also don't get confirmation of whether people far away are looking at us, or if they're looking at someone next to us. Thus we don't really know if they are. For me, both of these situations (thinking they are looking at me and finding they aren't, and seeing people look at me in response to my looking their way) happen frequently. I'm not sure our senses are that good at off-angle 'who's staring at me' though; instead I think we're just really well optimized to assume that just in case. Our brain is phenomenal at filling in the blanks visually, and making inferences based on important survival signals like where others are paying attention.
- Simon_says 8y ago
  Who is saying you can't tell apart 60fps from 120fps? Ludicrous statement.
- p1esk 8y ago
  Re frame rate: I believe 10kHz is considered a stroboscopic-artifacts detection threshold. Michael Abrash mentioned 300-1000Hz is required for low resolution VR (1080p). Higher rates for higher resolution. So yeah, the current 240Hz displays don't quite cut it. https://www.blurbusters.com/blur-busters-law-amazing-journey-to-future-1000hz-displays-with-blurfree-sample-and-hold/ https://www.blurbusters.com/blur-busters-law-amazing-journey...
  - p1esk 8y ago
    In fact, this is a great video demonstrating motion blur even at 1700Hz: https://youtu.be/PmAhJO6Vp3Y https://youtu.be/PmAhJO6Vp3Y I mean, the blur there is very slight, but still!
- sgc 8y ago
  Please excuse my lack of technical biological vocabulary. Here is my take on the issue: The error in reducing the fps to that of the human eye is that there is no guarantee the two are in sync. To guarantee I will actually see 72 fps (or x fps) as intended, the manufacturer needs to take into account the amount of time each frame is displayed, as well as the human response to changing frames on the screen during one "frame" of the eye. How many times should a pixel refresh during one observation to create a lifelike scene for the human eye? Something analogous can be said for dpi, and the fact that we can't see a specific pixel doesn't mean that each of our eyes' "units of resolution" correspond perfectly to where a pixel is on the screen. If we are seeing the intersection of four pixels at once but only seeing subpixels of each one that don't correspond to the intended color when taken together, theoretically all the color is falsified. If we are instead seeing a number of complete pixels in each of our own visual pixels, there is less chance of this. Further, the spacing between pixels varies by manufacturer, and this can have effects on the required resolution.
  - sitharus 8y ago
    That’s an interesting idea. The human eye (and the brain in general) isn’t a clocked system, different parts work at different speeds. You can see this yourself if you have an old fluorescent lamp that works on the mains frequency. You won’t perceive the flicker in the main part of your vision because the colour receptors aren’t that fast. However the edges of your vision where the rods dominate can perceive a 50/60hz flicker. The same is true of visual resolution. You only have high resolution sight in a tiny portion of your vision, the rest is much lower resolution and your brain uses a combination of rapid eye movements and spacial memory to fill in the blanks. Additionally one of the issues with perception of a pixel is your eyes have nothing like a pixel grid, it’s pretty random. You can see this if you use a digital camera to take a photo of a screen, you can see interference patterns as the grids align and unalign. This makes the whole equation very complicated, certainly nothing I can answer. I guess I’ll have to find an 8k/120hz display and find out.
    - AngryData 8y ago
      Florescent light flicker is especially obvious if you get your eyes dilated. I thought I was tripping out or something after an eye appointment because of it.
_ph_ 8y ago
I don't have good eyesight (far and shortsighted), so reading can be sometimes difficult for me. I was surprised how much easier the iPhone OLED screen (458dpi) is for reading than the 326 dpi LCD. The screen resulution difference made the iPhone XS worth it for me alone. Also, while I cannot "see" pixels on a 1x screen, a retina screen (e.g. iMac 5k) is much easier for reading too.
- conanthe 8y ago
  Mine has 570 PPI and I can easily see that text is pixelated although I cannot see individual pixels.
  - hu3 8y ago
    wow, which phone is that?
    - Spare_account 8y ago
      I'm not the person you replied to but the Samsung S8 has that PPI https://www.samsung.com/global/galaxy/galaxy-s8/specs/ https://www.samsung.com/global/galaxy/galaxy-s8/specs/ > Galaxy S8 5.8" Quad HD+ Super AMOLED (2960x1440) 570 ppi
  - ksec 8y ago
    Because if you discount the Green Dot, the Red and Blue only has 400PPI.
- npunt 8y ago
  The ppi don't tell the full story with OLED vs LED, since OLED has a different sub pixel arrangement (pentile) that isn't as sharp / legible. On the other hand, OLED has better contrast. It may not be pixels that matter in this case.
  - Wowfunhappy 8y ago
    Is this universally true for all OLED screens? I thought it was just a cost-saving measure by some manufacturers.
cryptonector 8y ago
Text? But we're talking about moving pictures. You're not gonna notice. Also, frankly, the last thing I worry about every day is whether I can turn off anti-aliasing yet. Text has been comfortable on computer monitors for a long time now.
ekianjo 8y ago
why focus on text? Video is moving pictures for the most part. You probably cant see any difference at all when there is enough movement.
philjohn 8y ago
Similarly, I can get acceptable framerates gaming at 4K on a 27" monitor with an RX 480 for e-sport titles (Assetto Corsa, Project Cars 2 etc.) by disabling AA ... because at that resolution you don't Really need it any more.
ksec 8y ago
Agree and Yes but that is also assuming you want higher resolution for Stationary Text and Images, which in 99% of the cases isn't true on TV. And hence 4K Really is enough is most cases. The same could not be said about Computer Screen, i.e If you use the 4K Screen as a large Monitor you will notice how the quality might not be "perfect" from where you are usually sitting watching TV, but perfectly fine when you are using TV screen as play moving pictures. The same goes to Phone as well, despite Retina being good enough, you can tell how 400PPI LCD ( iPhone Plus ) still look better than 326 PPI ( iPhone "Number" )in stationary usage. ( OLED uses sub pixel so what ever advertised PPI are quite a lot bigger than it actually is, the blue and red colour dot in iPhone X / Xs OLED only has a Retina 326 PPI ) I do think there are some possible edge cases where 4K might not be good enough, even in the parent's reference example for possible worst case scenario. But we could have 5K or 6K. Going 8K takes ridiculous amount of bandwidth and processing power for... virtually little to no gain. I am more interested in Colour Space, does it mean we get Rec 2020?

by pkulak 8y ago

ramraj07 8y ago

This. People always keep forgetting that our brain is definitely capable of some amount of superres lotion calculations especially for very specific types of structures. One aspect I've always been fascinated about is how far away someone can be when I can still tell that they're looking at me and not the person next to me. Most of the time I can definitely not read any text (even at 16 pts) if it was held at that distance but I can subconscuously tell the subtle differences in the angle their eyeballs are at. Same thing with 60fps vs 120fps. People keep saying you can tell them apart but I sure as well can at least in some instances.

Paperweight 8y ago
It's also annoying when they say you shouldn't be able to tell that PWM headlights/taillights are flickering but I sure as hell can, at least!
- freyir 8y ago
  Yeah, and when they say Wi-Fi shouldn't make my brain tingle
  - tokyodude 8y ago
    you're being downvoted and I have no idea if it would actually be possible to be sensitive to wifi but I can hear my 2014 MacBook Pro process certain things and I don't mean the fan. No idea what triggers the processing "buzz" because it's not constant but certain cpu intensive operations make a buzz I can hear so I can certainly believe a similar buzz could come from a router's processor
    - Wowfunhappy 8y ago
      That's called coil whine! It could happen in a router, but it seems unlikely in such a low power device.
      - antsar 8y ago
        I’ve used a 5-port ethernet switch (even lower power than a router) with very substantial coil whine. Like, “can’t tolerate it without headphones” substantial.
        leoleoleoleo 8y ago
        Tplink sg105e by any chance? I can hear mine from 3 meters away.
        antsar 8y ago
        Just checked. That's exactly the one.
      - AngryData 8y ago
        My graphics card had it terrible, well atleast until it died a two weeks ago. But it most often made the noise at an audible frequency during low power usage. When it got hit hard it stopped being a problem, but it could have just been pushing it outside of my audible range.
- monochromatic 8y ago
  Definitely noticeable when my eyes are moving quickly, glancing from one location to another.
  - Paperweight 8y ago
    Like when you're driving? :)
- btgeekboy 8y ago
  LED Christmas lights are the worst at this. I can definitely see the 60hz flicker, especially if there's movement.
cryptonector 8y ago
FPS matters a great deal in video games -- 120 is fantastically better than 30. FPS really doesn't matter that much in movies, much less TV shows, even action movies.
npunt 8y ago
Eyes can definitely tell more than 60hz, especially the rods in your peripheral vision. From what I remember in cog sci classes it was about 72hz that was just noticeable difference (JND), but I think this may be a bit higher in rods, and have small difference by gender. One way to tell is look at a CRT off-angle and adjust refresh rates until its no longer perceptible. Angle of eyes may be different and I'm more skeptical of whether we can tell if people really are looking at us off-angle or from considerable distance. On the one hand, we're certainly hyperaware of faces both in central and peripheral vision, as part of our brain is dedicated to face detection, and eyes have high contrast (black on white). And looking dead-on at someone's eyes we can infer where they're looking even from pretty far away. All of this of course serves a social / evolutionary / survival purpose. On the other, it may be that peripherally all we can tell that someone's is facing us and has open eyes, and this leads us to have a premonition that someone is looking at us. When we look up to confirm, this may or may not be true, but we'd be more likely to remember/encode that they were, thus making that sense err on the side of assuming people are looking at us. Add to that our own sudden shift in the angle of our face/eyes, which may cause them to react and look our way. We also don't get confirmation of whether people far away are looking at us, or if they're looking at someone next to us. Thus we don't really know if they are. For me, both of these situations (thinking they are looking at me and finding they aren't, and seeing people look at me in response to my looking their way) happen frequently. I'm not sure our senses are that good at off-angle 'who's staring at me' though; instead I think we're just really well optimized to assume that just in case. Our brain is phenomenal at filling in the blanks visually, and making inferences based on important survival signals like where others are paying attention.
Simon_says 8y ago
Who is saying you can't tell apart 60fps from 120fps? Ludicrous statement.
p1esk 8y ago
Re frame rate: I believe 10kHz is considered a stroboscopic-artifacts detection threshold. Michael Abrash mentioned 300-1000Hz is required for low resolution VR (1080p). Higher rates for higher resolution. So yeah, the current 240Hz displays don't quite cut it. https://www.blurbusters.com/blur-busters-law-amazing-journey-to-future-1000hz-displays-with-blurfree-sample-and-hold/ https://www.blurbusters.com/blur-busters-law-amazing-journey...
- p1esk 8y ago
  In fact, this is a great video demonstrating motion blur even at 1700Hz: https://youtu.be/PmAhJO6Vp3Y https://youtu.be/PmAhJO6Vp3Y I mean, the blur there is very slight, but still!
sgc 8y ago
Please excuse my lack of technical biological vocabulary. Here is my take on the issue: The error in reducing the fps to that of the human eye is that there is no guarantee the two are in sync. To guarantee I will actually see 72 fps (or x fps) as intended, the manufacturer needs to take into account the amount of time each frame is displayed, as well as the human response to changing frames on the screen during one "frame" of the eye. How many times should a pixel refresh during one observation to create a lifelike scene for the human eye? Something analogous can be said for dpi, and the fact that we can't see a specific pixel doesn't mean that each of our eyes' "units of resolution" correspond perfectly to where a pixel is on the screen. If we are seeing the intersection of four pixels at once but only seeing subpixels of each one that don't correspond to the intended color when taken together, theoretically all the color is falsified. If we are instead seeing a number of complete pixels in each of our own visual pixels, there is less chance of this. Further, the spacing between pixels varies by manufacturer, and this can have effects on the required resolution.
- sitharus 8y ago
  That’s an interesting idea. The human eye (and the brain in general) isn’t a clocked system, different parts work at different speeds. You can see this yourself if you have an old fluorescent lamp that works on the mains frequency. You won’t perceive the flicker in the main part of your vision because the colour receptors aren’t that fast. However the edges of your vision where the rods dominate can perceive a 50/60hz flicker. The same is true of visual resolution. You only have high resolution sight in a tiny portion of your vision, the rest is much lower resolution and your brain uses a combination of rapid eye movements and spacial memory to fill in the blanks. Additionally one of the issues with perception of a pixel is your eyes have nothing like a pixel grid, it’s pretty random. You can see this if you use a digital camera to take a photo of a screen, you can see interference patterns as the grids align and unalign. This makes the whole equation very complicated, certainly nothing I can answer. I guess I’ll have to find an 8k/120hz display and find out.
  - AngryData 8y ago
    Florescent light flicker is especially obvious if you get your eyes dilated. I thought I was tripping out or something after an eye appointment because of it.

_ph_ 8y ago

I don't have good eyesight (far and shortsighted), so reading can be sometimes difficult for me. I was surprised how much easier the iPhone OLED screen (458dpi) is for reading than the 326 dpi LCD. The screen resulution difference made the iPhone XS worth it for me alone. Also, while I cannot "see" pixels on a 1x screen, a retina screen (e.g. iMac 5k) is much easier for reading too.

conanthe 8y ago
Mine has 570 PPI and I can easily see that text is pixelated although I cannot see individual pixels.
- hu3 8y ago
  wow, which phone is that?
  - Spare_account 8y ago
    I'm not the person you replied to but the Samsung S8 has that PPI https://www.samsung.com/global/galaxy/galaxy-s8/specs/ https://www.samsung.com/global/galaxy/galaxy-s8/specs/ > Galaxy S8 5.8" Quad HD+ Super AMOLED (2960x1440) 570 ppi
- ksec 8y ago
  Because if you discount the Green Dot, the Red and Blue only has 400PPI.
npunt 8y ago
The ppi don't tell the full story with OLED vs LED, since OLED has a different sub pixel arrangement (pentile) that isn't as sharp / legible. On the other hand, OLED has better contrast. It may not be pixels that matter in this case.
- Wowfunhappy 8y ago
  Is this universally true for all OLED screens? I thought it was just a cost-saving measure by some manufacturers.

cryptonector 8y ago

Text? But we're talking about moving pictures. You're not gonna notice. Also, frankly, the last thing I worry about every day is whether I can turn off anti-aliasing yet. Text has been comfortable on computer monitors for a long time now.

ekianjo 8y ago

why focus on text? Video is moving pictures for the most part. You probably cant see any difference at all when there is enough movement.

philjohn 8y ago

Similarly, I can get acceptable framerates gaming at 4K on a 27" monitor with an RX 480 for e-sport titles (Assetto Corsa, Project Cars 2 etc.) by disabling AA ... because at that resolution you don't Really need it any more.

ksec 8y ago

Agree and Yes but that is also assuming you want higher resolution for Stationary Text and Images, which in 99% of the cases isn't true on TV. And hence 4K Really is enough is most cases. The same could not be said about Computer Screen, i.e If you use the 4K Screen as a large Monitor you will notice how the quality might not be "perfect" from where you are usually sitting watching TV, but perfectly fine when you are using TV screen as play moving pictures. The same goes to Phone as well, despite Retina being good enough, you can tell how 400PPI LCD ( iPhone Plus ) still look better than 326 PPI ( iPhone "Number" )in stationary usage. ( OLED uses sub pixel so what ever advertised PPI are quite a lot bigger than it actually is, the blue and red colour dot in iPhone X / Xs OLED only has a Retina 326 PPI ) I do think there are some possible edge cases where 4K might not be good enough, even in the parent's reference example for possible worst case scenario. But we could have 5K or 6K. Going 8K takes ridiculous amount of bandwidth and processing power for... virtually little to no gain. I am more interested in Colour Space, does it mean we get Rec 2020?