

How many frames can humans see - coliveira
http://www.100fps.com/how_many_frames_can_humans_see.htm

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ugh
Re Sensitivity to brightness: Human eyes can see single photons (well, one is
too few, but ten will definitly do it). Which means that if there is some
light - any light at all - we will see it. Not the direction (if we are
talking about single photons) but still. Oh, well, there will never be a TV
good enough :)

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d0mine
The first hit from Google:

 _The human eye is very sensitive but can we see a single photon? The answer
is that the sensors in the retina can respond to a single photon. However,
neural filters only allow a signal to pass to the brain to trigger a conscious
response when at least about five to nine arrive within less than 100 ms._
</quote>
[http://math.ucr.edu/home/baez/physics/Quantum/see_a_photon.h...](http://math.ucr.edu/home/baez/physics/Quantum/see_a_photon.html)

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ugh
Is this a correction? To quote myself: "(well, one is too few, but ten will
definitly do it)"

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Nwallins
It seems rather like an elaboration.

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jordyhoyt
Definitely. And it's pretty apparent that the responder wanted to actually
reference something, rather than just rely on someone saying, "10 photons
should be enough for anyone"

------
po
It is easy to prove that humans can perceive more than 60 frames per second:
wave your hand in front of a fluorescent light. They flicker at the same speed
as your electricity (in the US it's 60Hz) and you can easily see the motion
break down.

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ajross
That's not "perceiving" at 60Hz though. The eye is seeing an integrated image,
which happens to be of several "frames" of your hand lit mixed with gaps of
darkness. Effectively, you're seeing multiple strobes "at the same time".

You do get aliasing effects with strong strobing though, where your eyes can
see beating patterns in the image intensity. That's why some people get eye
strain looking at 60Hz displays; moving to ~70Hz or so generally fixes it.

But again, our visual systems do _not_ have the ability to distinguish between
individual events separated by 1/60th of a second. We just can't do it, and
trying to animate at that speed is purely wasted effort.

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csbrooks
>But again, our visual systems do not have the ability to distinguish between
individual events separated by 1/60th of a second. We just can't do it, and
trying to animate at that speed is purely wasted effort.

And yet, there's a very clear perceivable difference between a game running at
30hz and 60hz. How does that work?

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ajross
I don't buy it. Until someone shows me a real study (or even a demo where I
can verify the frame rate and see the effect for myself), I'm not going to
believe this "effect" exists.

Almost certainly, you're not seeing a 30Hz game. You're seeing a game running
at 30Hz typically and being annoyed by a handful of frames that take longer
than ~100ms. It's the outliers that are doing it, not the frame rate.

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DarkShikari
Then watch a 60fps video. Then decimate it to 30fps, and watch that. Or will
you claim that there are "outliers" in a constant framerate video, too?

The visual difference is so significant that television broadcasters have kept
interlacing _solely for the greater temporal resolution_ , despite the tens of
billions of dollars in inefficiencies that the legacy technology creates.

~~~
ajross
If the decimation does anything but average frames, then it's a lossy process
and of course there will be detectable differences. And if it does average
frames, it's susceptible to the aliasing issues I mentioned above (lighning
flashes become gray blurs, etc...)

The question was if there's a single game (or video) you can point me to that
(1) has a solid 30Hz frame rate and (2) looks perceptibly "not smooth" for
some obvious definition thereof.

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DarkShikari
Sure.

Here, I'll give an example that doesn't even rely on high motion, flashing, or
other such tricks: a simple video game clip. This particular game engine has
its display locked to 60fps: the in-game time between two frames is absolutely
constant, so even if your computer is too slow to display in realtime, it will
simply output frames slower. As a result, the FRAPS'd capture of the game is a
perfect smooth 60fps no matter what.

Additionally, it doesn't have any single-frame effects that would be visually
aliased (e.g. lightning), nor does it have any sort of motion blur.

<http://mirror05.x264.nl/Dark/testfps1.mkv>
<http://mirror05.x264.nl/Dark/testfps2.mkv>

Don't look at the filesizes (obviously, 60fps will be larger), and don't go
checking the file info or whatever. Just play them in your favorite media
player.

I'm pretty sure you'll be able to tell which is 60fps.

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ajross
Uh... then why is there a frame rate counter in the bottom right of the screen
giving variable numbers between 40-70? :)

I agree that the smaller file looks jumpier. But it's still reporting the same
frame rates as the bigger file, which leads me to believe the jumps are an
artifact of translation somewhere. Certainly nothing seems to be "locked".

~~~
DarkShikari
_Uh... then why is there a frame rate counter in the bottom right of the
screen giving variable numbers between 40-70? :)_

Because that's the rate of the frames being displayed during capture. Again,
the in-game time between two frames is the same, so if it captures at 50fps,
that just means the game runs at 50/60=5/6 times normal speed.

It's similar to how you can capture a 1000fps recording in Counterstrike: the
game doesn't actually have to _run_ at 1000fps, it just slows down the game
accordingly.

 _I agree that the smaller file looks jumpier. But it's still reporting the
same frame rates as the bigger file, which leads me to believe the jumps are
an artifact of translation somewhere. Certainly nothing seems to be "locked"._

It sounds like your media player is broken, because ffmpeg gives 60fps for the
higher framerate file and 30fps for the lower one.

------
est
What's the resolution and bitrate of a general human eye?

I have a theory: the ultimate limit of broadband upgrading movement is our
brain's whole throughput. After that individual consumers' demand will slow
down and the broadband market will be dedicated for industrial broadband
market. :)

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Retric
That's a hard problem.

The human eye is only ~2 megapixels but it's focused on a small part of your
field of view. So if you wanted to fool the eye you either need to track what
it's looking at or to create a huge high resolution screen most of which is
ignored. Add in the ability to focus and you suddenly need to add depth
information and a display that can handle it or you will not fool the eye. Now
add the fact that most people have 2 of them and it gets even more insane.

PS: Video cards have far higher internal bandwidth than external bandwidth for
a reason. Focusing on the brains bandwidth is not going to be enough.

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wensing
Fascinating, but one bit of feedback--I really would like to pass this on to a
couple of young, budding scientists, but I can't because of the examples:
murder, people being stabbed with an icepick, etc. Out of all the movies this
is what they choose? _sigh_

Please, writers--choose your examples with a broad audience in mind.

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CUViper
3dfx had a demo of this a while back. (11 years ago!) It would show 60/30/15
fps side-by-side, so you could better compare how the frame-rate impacts you.
I found it archived here: <http://www.falconfly.de/artwork.htm>
<http://www.falconfly.de/downloads/3dfxdemo-3060hz.zip>

You're likely to need a Glide wrapper too:
[http://www.sierrahelp.com/Utilities/DisplayUtilities/GlideWr...](http://www.sierrahelp.com/Utilities/DisplayUtilities/GlideWrappers.html)

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motters
The trouble is that the higher the frame rate the less photons are captured by
the light sensitive elements, and so the larger the shot noise becomes.

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radley
Follow this up with his other useful sites including:

<http://100-dating-tips.com>

<http://in-my-opinion.org>

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middus
BTW: These are other sites by the same author.

I think we should dismiss his 100fps articles based on the fact that he
operates a strange dating tips site.

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middus
whoops, this is missing a not. "we should not dismiss ..." sorry about that!

~~~
cliveholloway
There was me thinking it was sarcasm - works both ways :)

