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The more obvious example is to watch a video encoded at 10 frames per second followed by a 30 fps video. Does it look different? If yes, something's wrong with

The more obvious example is to watch a video encoded at 10 frames per second followed by a 30 fps video. Does it look different? If yes, something's wrong with the statement There are plenty of examples on YouTube if anyone's interested.

mrob 9y ago
That's not a fair comparison, because we can distinguish very high frame rates (eg. 1000fps vs 3000fps) by watching how the perceived image changes in reaction to eye movement. Consider an LED strobing at 100Hz. This is above the flicker fusion threshold, so with motionless eyes it will appear steady, but if you flick your eyes from side to side you will see multiple images (phantom array effect). This is limited to some extent by saccadic masking, but never perfectly, and saccadic masking strength varies from person to person. Similarly, limited frame rate makes it impossible to keep the image at exactly the same place on the retina during smooth pursuit eye tracking, causing perceived blur that wouldn't be seen with a real life moving object. Seeing a difference with 1000fps video doesn't mean we have 1ms temporal resolution perception, it just means some test signals allow conversion of temporal information to spatial information by eye movement. It doesn't generalize to arbitrary visual events. To investigate keyboard latency sensitivity properly there's no substitute for ABX testing of actual keyboards.
tomxor 9y ago
even the difference between 30 and 60 is pretty clear to most, I find watching movies at 60fps reeeally weird, it feels too real... I never actively look for the video framerate before, i just notice it, it's that obvious.
- mort96 9y ago
  I, on the other hand, having grown up with mostly playing games at 60 FPS (the PS2 ran the games I played at 60 FPS, back when console games prioritized gameplay over looking pretty in screenshots), and have moved on the 144 FPS on PC, find the 24 FPS used in cinemas to feel agonizingly choppy. Especially when there’s a big sweeping paniramic shot. It sometimes takes me out of the experience. I really liked the 48 FPS when watching the hobbit movies.
  - tomxor 9y ago
    I've grown up with FPS games too so it's not like i'm not used to 60FPS... i'm just saying from a film watching perspective, it starts feeling game like. There's been a number of articles dedicated to this perception, the general preference (whether you are consciously aware of it or not) is for <60FPS in film, the reasoning is that it gives this sort of dreamy state of perception, much like an animation, it relies on your subconscious to fill in the gaps, it makes a film feel more like a story than a documentary. On the other hand I agree that in some scenes this doesn't work well, fast moving wide angle shots of landscapes look awful. It will be interesting if film makers care enough about this detail in the future to play with it, perhaps as a newly adjustable dimension to film making (variable frame rate). So long as you don't consciously perceive the low frame rate (i.e it's matched to the movement of the scene) I think 24fps is ok, and preferable when it somehow activates that visually creative part of your visual perception. This would even be compatible with existing tech if you simply chose a high frame rate which is a multiple of the various frame rates you want to choose for different scenes.

mrob 9y ago

That's not a fair comparison, because we can distinguish very high frame rates (eg. 1000fps vs 3000fps) by watching how the perceived image changes in reaction to eye movement. Consider an LED strobing at 100Hz. This is above the flicker fusion threshold, so with motionless eyes it will appear steady, but if you flick your eyes from side to side you will see multiple images (phantom array effect). This is limited to some extent by saccadic masking, but never perfectly, and saccadic masking strength varies from person to person. Similarly, limited frame rate makes it impossible to keep the image at exactly the same place on the retina during smooth pursuit eye tracking, causing perceived blur that wouldn't be seen with a real life moving object. Seeing a difference with 1000fps video doesn't mean we have 1ms temporal resolution perception, it just means some test signals allow conversion of temporal information to spatial information by eye movement. It doesn't generalize to arbitrary visual events. To investigate keyboard latency sensitivity properly there's no substitute for ABX testing of actual keyboards.

tomxor 9y ago

even the difference between 30 and 60 is pretty clear to most, I find watching movies at 60fps reeeally weird, it feels too real... I never actively look for the video framerate before, i just notice it, it's that obvious.

mort96 9y ago
I, on the other hand, having grown up with mostly playing games at 60 FPS (the PS2 ran the games I played at 60 FPS, back when console games prioritized gameplay over looking pretty in screenshots), and have moved on the 144 FPS on PC, find the 24 FPS used in cinemas to feel agonizingly choppy. Especially when there’s a big sweeping paniramic shot. It sometimes takes me out of the experience. I really liked the 48 FPS when watching the hobbit movies.
- tomxor 9y ago
  I've grown up with FPS games too so it's not like i'm not used to 60FPS... i'm just saying from a film watching perspective, it starts feeling game like. There's been a number of articles dedicated to this perception, the general preference (whether you are consciously aware of it or not) is for <60FPS in film, the reasoning is that it gives this sort of dreamy state of perception, much like an animation, it relies on your subconscious to fill in the gaps, it makes a film feel more like a story than a documentary. On the other hand I agree that in some scenes this doesn't work well, fast moving wide angle shots of landscapes look awful. It will be interesting if film makers care enough about this detail in the future to play with it, perhaps as a newly adjustable dimension to film making (variable frame rate). So long as you don't consciously perceive the low frame rate (i.e it's matched to the movement of the scene) I think 24fps is ok, and preferable when it somehow activates that visually creative part of your visual perception. This would even be compatible with existing tech if you simply chose a high frame rate which is a multiple of the various frame rates you want to choose for different scenes.