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jeanlain

macrumors 68020
Mar 14, 2009
2,430
933
Pure placebo. Just think a moment: Normal reaction delay for humans is 200-300ms.
What does reaction delay have to do with perception of fluidity? By your metric, everything should be perfectly smooth above 5 fps, which clearly isn't the case.
 

edddeduck

macrumors 68020
Mar 26, 2004
2,061
13
What does reaction delay have to do with perception of fluidity? By your metric, everything should be perfectly smooth above 5 fps, which clearly isn't the case.

Correct, also that figure is not even useful for the delay between user input and game reaction. The 200ms delay on reaction time is how fast you can react to something happening however you can perceive things much faster than that, after all within the 200ms mentioned the human eye needs to pick up the movement, process it and react.

This is why you need much lower lag than 200ms on input devices change a mouse to have a 200ms delay and it amazing how it almost becomes unusable for any precision actions unless you move very slowly as your brain perceives and tries to compensate for the lag.

Edwin
 

edddeduck

macrumors 68020
Mar 26, 2004
2,061
13

Well that video is not completely smooth it appears to pulse whenever the motion speed increases. I know this might be obvious to many reading but the speed of the motion in the game also effects the feeling of smoothness, this is why fps is very important in racing and fps games but less so in turn based strategy games with slower movements.

For example in a racing game:

a) if I cam traveling at walking pace the amount the difference between frames is very slight (lets say under 10cm in game measurements per frame at 14fps) as I am moving slower. This in turn helps make the animation appear smoother as the difference between frames is smaller making everything seem smoother.

b) If I do the same test at 200mph the difference between the frames is now in the region of meters not centimetres per frame. This means the difference between the frames is much larger making the frame rate seem more choppy than before.

You can see this effect in the video you link to, in parts it seems more choppy than others and this happens when you have faster movement (bigger difference between frames) on screen. However this effect is hard to tell for sure as the video is not running at 14fps but much standard 30fps and the encoder is mashing it together giving you not quite the same experience as if you saw it running at 14fps as it will blend the frames a little.

Another example is how a game appears to get slower when turning around at speed in an fps, usually the frame rate has not altered at all just the difference between each frame in the game world is a lot bigger making the game feel slower and less responsive compared to turning round slowly.

This test above is pretty easy to reproduce, you could even do the test using two flicker books with both small and large motion and testing them. Your eyes and brain will make the slower motion one look smoother compared to the large motion one even though the fps is the same on both.

Edwin
 

SingularityG

macrumors 6502
Jun 7, 2012
338
0
Well that video is not completely smooth it appears to pulse whenever the motion speed increases. I know this might be obvious to many reading but the speed of the motion in the game also effects the feeling of smoothness, this is why fps is very important in racing and fps games but less so in turn based strategy games with slower movements.

For example in a racing game:

a) if I cam traveling at walking pace the amount the difference between frames is very slight (lets say under 10cm in game measurements per frame at 14fps) as I am moving slower. This in turn helps make the animation appear smoother as the difference between frames is smaller making everything seem smoother.

b) If I do the same test at 200mph the difference between the frames is now in the region of meters not centimetres per frame. This means the difference between the frames is much larger making the frame rate seem more choppy than before.

You can see this effect in the video you link to, in parts it seems more choppy than others and this happens when you have faster movement (bigger difference between frames) on screen. However this effect is hard to tell for sure as the video is not running at 14fps but much standard 30fps and the encoder is mashing it together giving you not quite the same experience as if you saw it running at 14fps as it will blend the frames a little.

Another example is how a game appears to get slower when turning around at speed in an fps, usually the frame rate has not altered at all just the difference between each frame in the game world is a lot bigger making the game feel slower and less responsive compared to turning round slowly.

This test above is pretty easy to reproduce, you could even do the test using two flicker books with both small and large motion and testing them. Your eyes and brain will make the slower motion one look smoother compared to the large motion one even though the fps is the same on both.

Edwin

Edwin, that was a joke...or at least I meant it that way.:eek:
 

the8thark

macrumors 601
Original poster
Apr 18, 2011
4,628
1,735
Pure placebo. Just think a moment: Normal reaction delay for humans is 200-300ms. 1 frame at 60fps has roughly 17ms - It is impossible for the brain to react to anything so fast, it would need 12+ frames for a fast reaction + the time for the movement of the arm/hand/fingers.

What really is important: vsync to avoid tearing and a stable framerate. Then even 30fps is more then enough.

Firstly thanks for all of the comments on this topic. I learnt some things here. Secondly the comment I am quoting made me think of baseball or cricket. The batter has to see the ball, let the brain compute the image it saw and then make the bat swing. And if I remember the TV show I saw on this, they said it takes about 250ms to do all this and then start the swing. That's about the time of an eye blink.

I think (relating this back to fps) that the brain has a limit at which it can interpret data from the eyes. Past that I think FPS really has it's retina. By that I mean, we all know what a retina screen is, but I think we'll work out what the max fps is such that the majority of people won't be able to tell the difference between that and a higher fps.

Honestly I'm no videophile or anything but I can tell for the most part the differences between 320/45/60 fps. But past 60 and it all looks the same to me. I have seen 120hz screens in the store, hideously pricey they were but I looked at them and didn't see anything I can remember being so special about them. But they were just playing a movie on them, and nothing like fast paced sports or anything that could benefit from 120hz.

"Another example is how a game appears to get slower when turning around at speed in an fps, usually the frame rate has not altered at all just the difference between each frame in the game world is a lot bigger making the game feel slower and less responsive compared to turning round slowly."

I agree with this too.

Will we say the fps's "Retina" is 60 fps? Or will they classify it at 120 fps. I know many companies would like it to be 120fps as they are trying to sell their 120hz screens. So many different viewpoints on this. Glad this topic is trying to make sense of them all.
 

edddeduck

macrumors 68020
Mar 26, 2004
2,061
13
Will we say the fps's "Retina" is 60 fps? Or will they classify it at 120 fps. I know many companies would like it to be 120fps as they are trying to sell their 120hz screens. So many different viewpoints on this. Glad this topic is trying to make sense of them all.

60 is the lowest frame rate that you could claim that on, after that you get diminishing returns. I do like 120fps on a 120 Hz screen especially with fast movement and I can notice it is side by side with 60Hz but its not a massive deal to me.
 

arashb

macrumors 6502
May 3, 2009
256
0
When you look at a car on the freeway and notice there tires. Don't you ever notice it sometimes giving the illusion of going backwards? That's when your brain can't keep up with the speed of the rotation, so there is a limit. Which would theoretically be when the wheel looks like it's at a standstill.

I wonder if someone can create a program and a 120hz display is strong enough to have a wheel spinning where someone could just test themselves.

For example, you see a standstill wheel when a car is rolling at 60 mph => 1065 inches per second
Wheel circumference = ~25 inches +/-
42.6 rotations/second

If 60 mph is the first speed your eyes start to perceive a standstill on a tire with a circumference of 25 inches then you refresh an image at 42.6 hz.

I think it works? If you're really interested that is :p. After I did the calculations it seems kinda of disappointing since 42.6 hz is a low number. But the inputs aren't exactly right.
 
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