Mythbusting: "Human eye cannot see beyond 60 FPS"

[May90]

So many people keep repeating this myth all over the Internet, that I decided it would be a good idea to bust this myth right here, once and for all. So, let's get started.

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First of all, the core statement is a nonsense. There have been many reports from different reaction tests that people can react to visual signals in less than 1 ms - this corresponds to 1000 FPS.

Now, where did this myth about "60 FPS" came from in the first place? Most LCD monitors today, let alone 10 years ago, have refresh rate of 60 Hz. On such monitor, no matter how much FPS your application, such as video game, has, you will see only 60 Hz, and additional frames will be ignored. On such monitor, even if your game has 1000 FPS, you will still essentially see 60 FPS.

Now take an old good CRT monitor. CRT monitors are good for this because their image is fully dynamic, that is every frame is drawn from scratch, while LCD monitors do not effectively draw frames that are not very different from each other, they only draw the difference. In dynamic scenes CRT and LCD monitors are similar in this regard.
Most good CRT monitors used to show 85-120 Hz. When you set your refrest rate on such monitor to 60 Hz, you can clearly see extreme flickering. When you set 85 Hz, flickering becomes bearable, but still noticeable. 120 Hz - flickering is almost gone. The difference between 120 Hz and 240 Hz is still noticeable if you place two monitors close to each other and stare at them attentively, but it is very slim.

Let's return to LCD monitors since that's what most people use today. I want to make a very important statement here that people arguing about FPS often do not fully understand:

How much FPS you can see depends on the scene you watch.

Imagine if the scene is just Windows desktop, without any activity on it. How much FPS do you need? Right, 0.
Now, imagine if a dot moves on your screen at speed of 1 pixel per second. Since the monitor cannot show "half pixels", you don't need more than 1 FPS to see this as perfectly smooth as your display resolution allows.

Imagine now an object that moves from the left edge of your screen to the right. It goes at speed of 200,000 pixels per second, while you have a resolution of 1920x1080. How much FPS do you need to notice this object? Since it shows on your screen for 1080/200,000 = 5.4 ms, you need 1000/5.4=186 FPS to consistently see it on your screen.
What does it all mean? If you use your usual 60 FPS, in about 66% cases you won't even pick a glance at this object. If you use 240 FPS, however, you will see it cross your screen every single time. And, since your eye is theoretically able to see much more FPS than that, you WILL actually see this object.

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So, here is the thing. When you say that you cannot see any difference beyond 60 FPS, first of all make sure that you are actually looking at more than 60 FPS. You cannot see more than 60 FPS on a 60Hz monitor no matter what, since the monitor itself will always show exactly 60 FPS. Then, make sure that you are actually looking at highly dynamical scenes, not just looking at your desktop moving icons around (although between 60 FPS and 120 FPS, I bet, you will see the difference even there). Finally, account for the habit: if you've been using 60 FPS for 10 years and then suddenly receive a 120 Hz monitor, you might not see the difference clearly right away since your eye is used to staring at the old screen. Give it some time, maybe, a day - then revert to the old refresh rate, and you will IMMEDIATELY see a HUGE difference by just moving mouse cursor around. You will see so many frames skipped, you will be shocked that you've never seen them before.

So, how many FPS do we need? Depends on the applications you use, of course. If you are interested only in web browsing and office work, you are unlikely to really need anything beyond even 30 FPS. If you play some slow-paced games like Hearthstone, 60 FPS is fine. If you play all kinds of games, including RPG, FPS, RTS, etc., 120 FPS will benefit you a lot. And if you are a hardcore FPS gamer, the more FPS you have, the better, 240 FPS and beyond will be just perfect.

TL;DR:
- Human's eye can see up to 1000 FPS and, perhaps, above.
- 60Hz monitor will always show 60 FPS, no matter how much FPS your game is able to provide.
- High refresh rates are noticeable only in dynamic scenes; in slow or static scenes you rarely will see any difference beyond 30 FPS.

Also, notice that it is my personal understanding of the problem. I may be wrong somewhere - if so, please feel free to correct me. Just remember: before saying stuff like "I cannot see anything beyond 60 FPS", make sure that you've actually tried it on scenes that are able to deliver a real difference - I guarantee that you will see a difference up to 200 Hz, at least, with the right way of testing.

[Remilia]

Human eyes see whatever the brain handles. Doesn't matter what FPS it is. If a person had some theoretical medical disease that causes issue in seeing high motion and indeed can't see past 20 fps then the theoretical person indeed can't. Sticking a number is pointless honestly.

[Lubricious]

The only proof you need is to go to an electronics store and watch a TV with high hz/FPS. The difference is so astounding that the super high refresh rate TV's look unnatural or even uncomfortably smooth and clean. Like looking through a window instead of into a monitor. So yes, you most definitely can see a difference. I know I sure can, and if I can I'm sure almost anyone can.

Edit: nerfed the hyperbole

[MonsieuRoberts]

This is all the proof you need.

[apepi]

Remember the 48 frames of The Hobbit?

[Remilia]

This is all the proof you need.

I prefer this
http://testufo.com/
has more stuff.

[MonsieuRoberts]

I prefer this
http://testufo.com/
has more stuff.

An even more specific comparison.

[May90]

This is all the proof you need.

I prefer this
http://testufo.com/
has more stuff.

Well, I don't think many people have doubt that there is a significant difference between 30 and 60 FPS. Beyond 60 FPS, however, many people believe that there is no difference. Which is strange, considering that just 10 years ago CRT monitors were still dominating the market and 60 FPS there was not even considered viable by most people due to terrible shimmering; the reasonable refresh rate started at 85Hz, and for good monitors 120Hz was a must.

Also, I think, many people just see a game on a 60Hz monitor showing 200 FPS and think, "Hmm, I don't see much difference". So, when someone tells them about 120Hz, they think of 120FPS on a 60Hz monitor...

That's why the best way to demonstrate the difference to a doubter is to say, "Just look at 120Hz". Before they actually see it for themselves, they will often use weirdest arguments to insist on their opinion. Such as, "60Hz was chosen as the mainstream resolution because it is the highest a human can see"...

[glo]

Your eyes don't see in frames, they see in reflections of light processed by a brain that doesn't operate on a "X executions per clock" basis.

Really, that's the only argument one needs to use if someone claims otherwise.

[Cows For Life]

Well, I don't think many people have doubt that there is a significant difference between 30 and 60 FPS. Beyond 60 FPS, however, many people believe that there is no difference. Which is strange, considering that just 10 years ago CRT monitors were still dominating the market and 60 FPS there was not even considered viable by most people due to terrible shimmering; the reasonable refresh rate started at 85Hz, and for good monitors 120Hz was a must.

Also, I think, many people just see a game on a 60Hz monitor showing 200 FPS and think, "Hmm, I don't see much difference". So, when someone tells them about 120Hz, they think of 120FPS on a 60Hz monitor...

That's why the best way to demonstrate the difference to a doubter is to say, "Just look at 120Hz". Before they actually see it for themselves, they will often use weirdest arguments to insist on their opinion. Such as, "60Hz was chosen as the mainstream resolution because it is the highest a human can see"...

Just because the eye can detect slight phosphor dimming at 85hz doesn't mean it can detect discrete images at 85hz.

[apepi]

I would rather be more worried about us being able to having dimishing returns on resolution.

People saying we can only have 60fps are people who make tvs and games to make people think it does not matter.

[Deleted]

I'm pretty sure I saw the difference between 60 fps and 90-100 fps. It looked really, really fluid all of a sudden.

[ChaosWolf]

https://www.youtube.com/watch?v=4I5Q3UXkGd0

Watch this.

[Yunru]

It depends on a person and its brain processing power.
People with photo memory will see more fps...thats for sure.
60 is just standart.

[loki504]

Also, notice that it is my personal understanding of the problem. I may be wrong somewhere - if so, please feel free to correct me. Just remember: before saying stuff like "I cannot see anything beyond 60 FPS", make sure that you've actually tried it on scenes that are able to deliver a real difference - I guarantee that you will see a difference up to 200 Hz, at least, with the right way of testing.

you made 1 mistake here. you can see the diffrence between 60/120 or even 200 fps but that doesn't mean the rest can.
just because arjan robben runned 37km/u doesn't mean the rest of the world can. and like remilia said its how much the brain can handle. sure some can see maybe 1000fps. but i'm also 100% sure some are stick with 120 or maybe even 60.

[haxartus]

Try this. It interpolates 30fps videos to 60. The difference is shocking, it feels like I'm watching through a window... I had to remove it because I'm so used to 30 that this looks unnatural, weird.

[May90]

Your eyes don't see in frames, they see in reflections of light processed by a brain that doesn't operate on a "X executions per clock" basis.

Really, that's the only argument one needs to use if someone claims otherwise.

Good notion. However, there is still a certain limit to how many frames the eye can see due to imperfections of the eye as an optical system, due to limit of our brain "speed", etc. Just this limit is much, MUCH higher than what we are used to on monitors. We can tolerate monitors at all not because their refresh rate is close to our "internal refresh rate", but because our brain is used to always see everything fluid, so it essentially adds lacking frames - but there is a limit to how much it can do it, and in fast moving scenes, even at 240Hz, I believe, it will sometimes fail.

Just because the eye can detect slight phosphor dimming at 85hz doesn't mean it can detect discrete images at 85hz.

Yes, but if the eye can see the difference between 60Hz and 85Hz on CRT monitor, it can see the difference between 60Hz and 85Hz on LCD monitor. CRT monitor draws a new picture every time while LCD just makes corrections to already existing image (effectively; technologically, it is not exactly so), but in highly dynamic scene, where every frame is strongly different from the previous one, the difference between two approaches ceases to exist.

you made 1 mistake here. you can see the diffrence between 60/120 or even 200 fps but that doesn't mean the rest can.
just because arjan robben runned 37km/u doesn't mean the rest of the world can. and like remilia said its how much the brain can handle. sure some can see maybe 1000fps. but i'm also 100% sure some are stick with 120 or maybe even 60.

That's true. However, there is absolutely no reason to claim anything about the number 60. Sure, some people have more eye sensitivity, some less. However, I've yet to find anyone who can't see the difference between 60 FPS and 120 FPS when actually looking at it. There is absolutely nothing magical about 60 FPS; one could just as well make any claims about, say, 173 FPS. 60 FPS is just a standard, but people often confuse it with some human's properties.

Try this. It interpolates 30fps videos to 60. The difference is shocking, it feels like I'm watching through a window... I had to remove it because I'm so used to 30 that this looks unnatural, weird.

Wow... I was wondering when something like this would appear. Need to test it now, definitely!

Of course, again, it is not perfect, and in fast moving scenes it may sometimes add "wrong" frames - that may be the reason of this feeling unnatural. However, potentially it is a very strong thing. Imagine if any game you would normally play at 20 FPS on highest settings you could essentially see at 60 FPS with very little difference! Wouldn't work for fast-paced FPS, I suppose, but for RPGs - certainly!

[minteK917]

The United states Air force have already toyed with human eye speed. Human eyes are different then screens and dont work on the same principles. But according to their finding using lights and darkness for trained pilots to see and accurately name a plane at fast speed. Many of their reactions speed to the flash of the image was as fast as 350 frame per seconds when its going from darkness to light and as low as 90 frame per second in the reverse.

You also have to know that the eye has a small kinda of memory reflection that last a few seconds. But yes its been a stupid myth overall.

[haxartus]

This is for videos though, I don't know how something like this could work for games.

[Nem2k]

I was going to write a long post to dispute your claim, but decided to just add to the discussion instead from a vision science/cognitive science perspective as that is my background:

I've never understood what people mean when they say "Human eye cannot see beyond 60 FPS" because its extremely vague

The human eye can receive and send sensory input to the brain at the speed of an action potential. 60fps works out to be around 1 frame every 17ms. A single action potential is on average slower than this. However, multiple retinal cells go to your visual system at a time. In essence vision works in parallel across the visual field which speeds up the processing of a scene. So yes, in theory, and assuming action potentials fire asynchronously, the visual system can receive information about visual changes at rates faster than "60fps" due to its parallel nature of processing. Your brain receives a lot of information through your eyes.

The issue here though is not at the sensory level. Just because your brain can receive a lot of sensory input really quickly does not actually mean very much. The issue, I believe, lies in attentional processing. You are not paying attention to everything in your visual field at the same time. This has been shown multiple times and there are many theories surrounding how it actually works. The problem is that the "framerate" of your attentional window is much slower than than that of your sensory systems. Sensory systems work at the speed of action potentials. But attention works on the order of hundreds of milliseconds. Many of my colleagues ignore responses to stimuli that occur faster than 100ms because that is usually considered to be an anticipated response. Even reflexive responses to stimuli typically happen slower than 100ms. This works out to be a measly 10fps.

So when people claim that human eyes cannot see beyond 60fps...what are they actually talking about? Because at one level, sure you can sense the change at high frame rates, but your attentional window is not fast enough to catch changes that happen so suddenly. So I don't know. It's an interesting topic but its a very complicated one with multiple levels at play, and I don't believe the claims are simply coming from refresh rates of monitors.