4 ms·

I'm working on an AR headset and we made some experiments with the human eye. I barely can notice the difference for motion above 120 fps. But my associate is a

I'm working on an AR headset and we made some experiments with the human eye. I barely can notice the difference for motion above 120 fps. But my associate is a retired fighter pilot and he can react to motion at ~280 fps.

emj 9y ago
How do you test that; can you measure how you react to motion at 120fps vs 280fps, or is it just a feeling?
- stanlarroque 9y ago
  It's not a feeling, we do the measures. It's like measuring your reaction time, few experiments are on screen and some are analogs. At the end you have a measure in a unit of time, and you deduce the fps from that
- valarauca1 9y ago
  In FPS there are people called "stat junkies" the name expresses its hobby well. You try to play for the best stats. Head shot ratio (how often you get head shots), KDR (kill death ratio). You could likely data mine from stat sites before before/after purchasing very high refresh rate monitors. OFC there maybe some bias to try harder once you drop >$400 on a hobby. In my own subjective experience 60 -> 144FPS was night and day. Roughtly ended up being a 50% pref improvement.
mattkrause 9y ago
There's got to be something else going on there. 280 frames/sec is about 3.5 ms/frame. Signals don't even leave the retina that fast, let alone propagate to brain areas linked to perception and action. Perhaps the higher frame rate makes the motion smoother, which allows the pilot to estimate and extrapolate an objects' motion more accurately, or something like that.
- wtallis 9y ago
  Smooth motion is definitely a big factor. Just look at things in terms of how fast something on screen (eg. the cursor) is moving in terms of pixels per frame. Moving a cursor horizontally across a 4k display in a relatively slow one second is 64 pixels per frame at 60Hz, which is significantly wider than the cursor itself. At 144Hz it's about 26 pixels per frame, and at 280Hz it would be about 14 pixels per frame. Even if you have a low-persistence display, you need to have a pretty high refresh rate to draw smooth motion. Hardly anything needs to be animated all the way down at 1 pixel per frame, but hardly anything currently comes at all close to that ideal strobe-free smoothness.
- GuyWIthLag 9y ago
  Actually, human eyes don't have a "frame rate" per se, or if you want there are different frame rates depending on the feature - and how far removed it is from the retina. Essentially, the retina itself can detect >300hz, then there's a bunch of processing as you go back the optic nerve that causes that number to drop for higher-level features.
  - mattkrause 9y ago
    Any chance you have a source for that? I'm legitimately curious, since I've never heard anything like that.
- hvidgaard 9y ago
  The visual system do not work in frames (well, on a fundamental level I supose it does, with the indivitual photons and nerve impulses being the smallest unit, but that is not a limit in practice). The information the retina captures is streamed continuesly to the brain, so higher FPS provides a higher temporal resolution for the visual experience. I don't think a fighter pilot inheriently react faster because of the resolution, but he is trained to detect motion in his peripheral vision. Perhaps he notice the smooth motion more than people who rarely train that part of their visual system. It would be interested to see how a trained and experience hunter would compare, as they often use peripheral vision as well.
mickronome 9y ago
In my hardcore gaming days using a fantastic Hitachi CRT monitor I did some basic experiments with refresh rates. My subjective results were somewhere in between the values you have as an example. I stopped noticing significant difference somewhere north of 160Hz, and at 200Hz they were barely perceptible. Very interesting to hear that someone has actually been measuring this in a more controlled way than I did some 18 years ago. It's also quite interesting how reluctant people are to even acknowledge the existence of something they themselves haven't noticed. Almost everyone refuted my eye witness account simply because they had read/heard that they eye can only notice <some number between 20-60> frames per secobd, and thus I couldn't possibly see any difference in motion above that threshold.

emj 9y ago

How do you test that; can you measure how you react to motion at 120fps vs 280fps, or is it just a feeling?

stanlarroque 9y ago
It's not a feeling, we do the measures. It's like measuring your reaction time, few experiments are on screen and some are analogs. At the end you have a measure in a unit of time, and you deduce the fps from that
valarauca1 9y ago
In FPS there are people called "stat junkies" the name expresses its hobby well. You try to play for the best stats. Head shot ratio (how often you get head shots), KDR (kill death ratio). You could likely data mine from stat sites before before/after purchasing very high refresh rate monitors. OFC there maybe some bias to try harder once you drop >$400 on a hobby. In my own subjective experience 60 -> 144FPS was night and day. Roughtly ended up being a 50% pref improvement.

mattkrause 9y ago

There's got to be something else going on there. 280 frames/sec is about 3.5 ms/frame. Signals don't even leave the retina that fast, let alone propagate to brain areas linked to perception and action. Perhaps the higher frame rate makes the motion smoother, which allows the pilot to estimate and extrapolate an objects' motion more accurately, or something like that.

wtallis 9y ago
Smooth motion is definitely a big factor. Just look at things in terms of how fast something on screen (eg. the cursor) is moving in terms of pixels per frame. Moving a cursor horizontally across a 4k display in a relatively slow one second is 64 pixels per frame at 60Hz, which is significantly wider than the cursor itself. At 144Hz it's about 26 pixels per frame, and at 280Hz it would be about 14 pixels per frame. Even if you have a low-persistence display, you need to have a pretty high refresh rate to draw smooth motion. Hardly anything needs to be animated all the way down at 1 pixel per frame, but hardly anything currently comes at all close to that ideal strobe-free smoothness.
GuyWIthLag 9y ago
Actually, human eyes don't have a "frame rate" per se, or if you want there are different frame rates depending on the feature - and how far removed it is from the retina. Essentially, the retina itself can detect >300hz, then there's a bunch of processing as you go back the optic nerve that causes that number to drop for higher-level features.
- mattkrause 9y ago
  Any chance you have a source for that? I'm legitimately curious, since I've never heard anything like that.
hvidgaard 9y ago
The visual system do not work in frames (well, on a fundamental level I supose it does, with the indivitual photons and nerve impulses being the smallest unit, but that is not a limit in practice). The information the retina captures is streamed continuesly to the brain, so higher FPS provides a higher temporal resolution for the visual experience. I don't think a fighter pilot inheriently react faster because of the resolution, but he is trained to detect motion in his peripheral vision. Perhaps he notice the smooth motion more than people who rarely train that part of their visual system. It would be interested to see how a trained and experience hunter would compare, as they often use peripheral vision as well.

mickronome 9y ago

In my hardcore gaming days using a fantastic Hitachi CRT monitor I did some basic experiments with refresh rates. My subjective results were somewhere in between the values you have as an example. I stopped noticing significant difference somewhere north of 160Hz, and at 200Hz they were barely perceptible. Very interesting to hear that someone has actually been measuring this in a more controlled way than I did some 18 years ago. It's also quite interesting how reluctant people are to even acknowledge the existence of something they themselves haven't noticed. Almost everyone refuted my eye witness account simply because they had read/heard that they eye can only notice <some number between 20-60> frames per secobd, and thus I couldn't possibly see any difference in motion above that threshold.