3 ms·

Music is extremely sensitive for timings, but when it comes to visuals you seem to adapt quickly and tolerate lag up to 1/10s, how is that !? And what about "hi

by z3t4 8y ago

Music is extremely sensitive for timings, but when it comes to visuals you seem to adapt quickly and tolerate lag up to 1/10s, how is that !? And what about "hidden" messages in videos (running as low as 30 FPS!) ? That only the subconscious can process. It seems that our human image processing only runs at around 30-60 FPS when idle, but can increase in stressful situations. I recall a study where people bungy jumping was able to read something off a clock during a jump, but not when safely on the ground.

romwell 8y ago
>Music is extremely sensitive for timings, but when it comes to visuals you seem to adapt quickly and tolerate lag up to 1/10s, how is that? Our visual systems are not optimized to give accurate, realtime representation of geometry around us. They evolved to give us a somewhat abstract representation that is most useful. There is a lot of post-processing involved between photons hitting your eye and your brain "seeing" things. In that post-processing, both geometry and time information are "corrected". The most striking example of this is saccadic masking[1]. Basically, your eyeballs move all the time, but you will never see that when you are looking at yourself in the mirror. However, look at your eyeballs on your selfie camera, and ta-dah! They move! That's because your eyes essentially block your visual processing pipeline while the eye is moving, and then backfill the missing frames. That's why if you move your eyes around rapidly while looking at an analog clock, you will perceive some seconds to last longer than others. The eyes are lying about how long things take. >Our human image processing only runs at around 30-60 FPS when idle, but can increase in stressful situations In general, our vision doesn't really have a "frame rate", and depending on how you define that concept, our "frame rate" goes well into the hundreds of FPS[0]. But something like what you said is happening. Visual perception of things gets on-the-fly adjustments as necessary. For example, baseball players see balls as being larger than you would see the same ball while being stationary at the same distance[2]. That's why, yes, we can get away with a lot of visual trickery, taking advantage of the visual post-processing pipeline (monitors giving the illusion of smooth motion is one example). However, this all doesn't mean we won't feel latency when it's there. As a good example, compare drawing a line with a pencil vs. drawing a line on a touchscreen device with a stylus. You will notice even the smallest latency. In fact, there is no device on the market where something simple as drawing a line following a stylus would happen fast enough for you to be fooled. As long as there is any visible distance between the tip of the stylus and the end of the line appearing on the screen, you will see it (or feel it), even if takes a very small time to fill that gap. Same with scroll latency: it's something you will not be able to see on a video recording of someone scrolling on a touchscreen, but you will absolutely feel the difference when you do it. And all that said, our aural perception is more sensitive to timing, and we also do Fourier transforms on the fly with our ears (that's how we can tell chords apart!), amonf other things. Our perception is an interesting thing. [0]https://www.pcgamer.com/how-many-frames-per-second-can-the-human-eye-really-see/ https://www.pcgamer.com/how-many-frames-per-second-can-the-h... [1]https://en.wikipedia.org/wiki/Saccadic_masking https://en.wikipedia.org/wiki/Saccadic_masking [2]https://www.thecut.com/2016/10/the-science-of-how-baseball-players-hit-fastballs.html https://www.thecut.com/2016/10/the-science-of-how-baseball-p...

by z3t4 8y ago

romwell 8y ago

>Music is extremely sensitive for timings, but when it comes to visuals you seem to adapt quickly and tolerate lag up to 1/10s, how is that? Our visual systems are not optimized to give accurate, realtime representation of geometry around us. They evolved to give us a somewhat abstract representation that is most useful. There is a lot of post-processing involved between photons hitting your eye and your brain "seeing" things. In that post-processing, both geometry and time information are "corrected". The most striking example of this is saccadic masking[1]. Basically, your eyeballs move all the time, but you will never see that when you are looking at yourself in the mirror. However, look at your eyeballs on your selfie camera, and ta-dah! They move! That's because your eyes essentially block your visual processing pipeline while the eye is moving, and then backfill the missing frames. That's why if you move your eyes around rapidly while looking at an analog clock, you will perceive some seconds to last longer than others. The eyes are lying about how long things take. >Our human image processing only runs at around 30-60 FPS when idle, but can increase in stressful situations In general, our vision doesn't really have a "frame rate", and depending on how you define that concept, our "frame rate" goes well into the hundreds of FPS[0]. But something like what you said is happening. Visual perception of things gets on-the-fly adjustments as necessary. For example, baseball players see balls as being larger than you would see the same ball while being stationary at the same distance[2]. That's why, yes, we can get away with a lot of visual trickery, taking advantage of the visual post-processing pipeline (monitors giving the illusion of smooth motion is one example). However, this all doesn't mean we won't feel latency when it's there. As a good example, compare drawing a line with a pencil vs. drawing a line on a touchscreen device with a stylus. You will notice even the smallest latency. In fact, there is no device on the market where something simple as drawing a line following a stylus would happen fast enough for you to be fooled. As long as there is any visible distance between the tip of the stylus and the end of the line appearing on the screen, you will see it (or feel it), even if takes a very small time to fill that gap. Same with scroll latency: it's something you will not be able to see on a video recording of someone scrolling on a touchscreen, but you will absolutely feel the difference when you do it. And all that said, our aural perception is more sensitive to timing, and we also do Fourier transforms on the fly with our ears (that's how we can tell chords apart!), amonf other things. Our perception is an interesting thing. [0]https://www.pcgamer.com/how-many-frames-per-second-can-the-human-eye-really-see/ https://www.pcgamer.com/how-many-frames-per-second-can-the-h... [1]https://en.wikipedia.org/wiki/Saccadic_masking https://en.wikipedia.org/wiki/Saccadic_masking [2]https://www.thecut.com/2016/10/the-science-of-how-baseball-players-hit-fastballs.html https://www.thecut.com/2016/10/the-science-of-how-baseball-p...