What is the "frame rate" of a human eye?

[dude8604]

Is it possible to compare it to that?

 

[BlackNinja]

if i remember correctly .. i read it somewhere and it said that it's around 80 fps. Perfect example would be to lower ur refresh rate of ur monitor to 60Hz .. u can see it flickers but if u set it to 85 hz or above the image seems to be solid with none of that eye-hurting stuffs. ..

 

[Mingon]

Search the Video forum their is always lots of heated discussions about FPS.

 

[JeremiahTheGreat]

if i remember correctly .. i read it somewhere and it said that it's around 80 fps. Perfect example would be to lower ur refresh rate of ur monitor to 60Hz .. u can see it flickers but if u set it to 85 hz or above the image seems to be solid with none of that eye-hurting stuffs. ..

I'm not sure on the specifics, but its because the phosphors decay (light intensity wise) very quickly and need to have the electron scan past it again in order for it to appear to be 'flicker free'.

On the contrary, on a LCD, you could have a refresh rate of 1, and it would be flicker free but of course you would only see the screen update once per second.


I personally believe above 60 FPS, (as in, it never dips below 60 and never pauses or anything) there is hardly any noticeable difference..

 

[Mingon]

The human eye can see in excess of 150fps, have a go with this

 

[CTho9305]

Originally posted by: Mingon
The human eye can see in excess of 150fps, have a go with this

cool. I cant get higher than ~60 fps, but 60 looks smooth to me...
edit: here is a clearer example of framerate differences.

 

[Tab]

Originally posted by: JeremiahTheGreat

if i remember correctly .. i read it somewhere and it said that it's around 80 fps. Perfect example would be to lower ur refresh rate of ur monitor to 60Hz .. u can see it flickers but if u set it to 85 hz or above the image seems to be solid with none of that eye-hurting stuffs. ..

I'm not sure on the specifics, but its because the phosphors decay (light intensity wise) very quickly and need to have the electron scan past it again in order for it to appear to be 'flicker free'.

On the contrary, on a LCD, you could have a refresh rate of 1, and it would be flicker free but of course you would only see the screen update once per second.


I personally believe above 60 FPS, (as in, it never dips below 60 and never pauses or anything) there is hardly any noticeable difference..

Not that I am disagreeing with you, when playing a game for instance or something interactive. You will start to notice the difference, you will fell it not see it.

 

[wfbberzerker]

i think i remember reading that the human eye sends about 24 images/second to the brain (it was either that, or 60, cant remember). im pretty sure that in addition to correcting the perspective (images are sent to the brain upside down, since the lens of your eye flips the outside world), it also blurs images if they are moving too fast (somewhat like the motion blur on TV).

 

[MrDudeMan]

Originally posted by: wfbberzerker
i think i remember reading that the human eye sends about 24 images/second to the brain (it was either that, or 60, cant remember). im pretty sure that in addition to correcting the perspective (images are sent to the brain upside down, since the lens of your eye flips the outside world), it also blurs images if they are moving too fast (somewhat like the motion blur on TV).

n/m

 

[Mingon]

yes...it is 24 images per second, not 60. i dont know if that is the same thing as all thi FPS babble, but i know for sure we cant see 150fps haha that is hilarious

Have you even tried either of the 2 programs posted ?

 

[wfbberzerker]

Originally posted by: Mingon

yes...it is 24 images per second, not 60. i dont know if that is the same thing as all thi FPS babble, but i know for sure we cant see 150fps haha that is hilarious

Have you even tried either of the 2 programs posted ?

i wouldnt trust that program...

 

[dolph]

the human eye doesn't see "frames," it has a constant stream. tests have proven that eyes can see an image that was flashed in 1/220th of a second and recognize it, thus indicating that we can see at least 220 fps. there is no proven limit to the amount of fps the eye can detect. at 24 fps, the eye makes a motion blur that creates the impression of movement.

 

[kylebisme]

who did this research dolph?

 

[dejitaru]

Ah yes, and there are nice little mental disorders which can drop it down to 1Hz.

fun stuff

 

[dolph]

snowman, check here

 

[CTho9305]

Originally posted by: wfbberzerker

Originally posted by: Mingon

yes...it is 24 images per second, not 60. i dont know if that is the same thing as all thi FPS babble, but i know for sure we cant see 150fps haha that is hilarious

Have you even tried either of the 2 programs posted ?

i wouldnt trust that program...

the one I posted comes with SOURCE CODE! Your eye may send only 24fps to the brain, but you can see jerks in <60 fps. 30fps motion blurred is pretty good, 60 non-blurred is also good.

 

[wviperw]

tests have proven that eyes can see an image that was flashed in 1/220th of a second and recognize it, thus indicating that we can see at least 220 fps

Hmm... I don't see how that proves the eyes can see @ >220fps. For example, lets say the eyes see at 30fps. That means in one second, the eyes will be able to distinguish 30 different images, therefore each image takes up 1/30 of a second. Lets say that this occurence of light (1/220) happens in the first frame of the second. Therefore, It could happen anytime between 0/220 and [(1/30)*220], which is about the first 7/220 parts of a second. So since it occurs inside a frame, one should be able to see it, correct?

Also, I don't think it quite works to apply an "fps" POV to the eyes anyway as they are analog/organic and we are trying to compare them to something digital (fps).

 

[KingofFah]

I agree with viper. We cannot get an accurate measure on our eyes' viewing capabilities. This is probably why there are so many different numbers coming up. What makes this even harder is that the human eye can increase and decrease its perception rate. Someone said something about the eye blurring images that are going to fast. This is true - temporarily. If you look at something that is blurring and start concentrating for long enough, eventually you will easily be able to see the blurring images and make distinctions. (Ever expand your registry all the way scroll down at a rate that you "cannot" see?. About 15 mins later you will be able to read every line that goes by, it is pretty cool). This is why we have so many variations of "frame rate" numbers. I like doing that to get my eyes receiving info a faster (call me sick and twisted if you want).

PS - Long time no see wviperw. I used to work for Q3Center.com as a map reviewer (King AKA MeTaLPuNk), and I reviewed a couple of your maps. Some guy cloned your map and tried to pass it off as his own, if you remember. Hehe.

 

[kylebisme]

dolph, as stated above, the guy is comparing apples and oranges there. furthermore i have read both his arcticles on the subject before and have come to the concusion that the auther is short a few cards in his deck.

 

[MrDudeMan]

Originally posted by: TheSnowman
dolph, as stated above, the guy is comparing apples and oranges there. furthermore i have read both his arcticles on the subject before and have come to the concusion that the auther is short a few cards in his deck.

lmao

 

[dolph]

more google searches didn't do anything to confirm any limit to frames per second the eye can distinguish differences between, if given enough time. as far as 1/220th of a second image, this is how it works: if the eye only takes an image 30 times every second, then that "1/220" image must be presented at one of the 30 times the eye refreshes, otherwise, it would go by unnoticed because the eye had already taken its snapshot. otherwise, the chances that the eye could catch that 1/220 image would be about 1 in 7 (30*7~220). if any links can be provided to prove otherwise, please post them, i'd like to know how it really works, too.

 

[wfbberzerker]

Originally posted by: dolph
more google searches didn't do anything to confirm any limit to frames per second the eye can distinguish differences between, if given enough time. as far as 1/220th of a second image, this is how it works: if the eye only takes an image 30 times every second, then that "1/220" image must be presented at one of the 30 times the eye refreshes, otherwise, it would go by unnoticed because the eye had already taken its snapshot. otherwise, the chances that the eye could catch that 1/220 image would be about 1 in 7 (30*7~220). if any links can be provided to prove otherwise, please post them, i'd like to know how it really works, too.

im not sure it works that way... (i might be wrong on this, but this is how i believe it works). since there are millions of color receptors and motion-detectors, each one fires a message to your brain at different times. thats why you cant refer to sight as a "frame rate," since, unlike a computer, your brain is not redrawing the entire image you see over and over. so, im sure if you took the average of all the times each receptor fires a message to your brain, it would come out to about 30 frames/sec. however, since there are constantly some firing all the time, you are able to perceive very small changes in images. but, when something is moving very fast, your receptors are not firing fast enough to register all the changes in the objects movements - hence the blurring when something moves fast.

 

[Goi]

Framerates and refresh rates are quite different when you're talking of a CRT monitor. CRT monitors don't show a single frame at a time, but rather they use an electron gun to draw dot by dot, line by line from left to right, top to bottom, and when the gun reaches the bottom, it traverses back to the top left corner and continues to draw the next "frame". As such, it is somewhat continuous. Also, as mentioned above, the phosphors of a CRT monitor don't hold the color/brightness indefinitely, but fades away with time, pretty quickly actually, which is why a high refresh rate is desired. Once the electron gun hits a spot in the CRT phosphor, that part will brighten up, but as the electron gun moves away to draw the next part, that part will start to fade away and decade. It happens so fast that at a lower enough refresh rate(60Hz) you will notice "flickering", as if the monitor is turning itself on and off discretely very quickly, when it fact its more like a pulsing effect.

Framerates in the strict sense however is pertaining to discrete frames. For example, if I show you a picture book with continuous pictures on each page, each one captured at a slight time difference from the previous one, and then if I flipped the book real fast, at some point you'd be interpreting the flipped image as continuous. If I flip it slow enough, you're gonna see a slideshow. This differs from the refresh rate example used above in that at any point in time you're viewing a complete frame, and every part of that frame holds its brightness/intensity for the full duration of the frame. In the refresh rate example though, the frame is only complete for a very small percentage of the time(depending on resolution/refresh rate), when the very last pixel is drawn. Also, by that time the brightness of the earlier drawn pixels would have decayed considerably, rendering them more or less 'black", unless you have a high enough refresh rate.

Gee, that was a chunk, hope it made some sense...

 

[ProviaFan]

I could be wrong on this, but IIRC the eye's receptors will shut down if the image that they pick up is not changing. The brain just makes you think that you're still seeing something from those receptors. If the image suddenly changes, there may be a slight delay before the receptors "wake up."

All of the links that I have seen point to various things that support the idea of human eyes seeing much more than 24 or 30 fps, but no one who has claimed that we can only see 24 or 30 fps has posted any research to back it up. Hmm....interesting. ;-)

From Dolph's link:

There is a common misconception in human thinking that our eyes can only interpret 30 Frames Per Second. This misconception dates back to the first human films where in fact a horse was filmed proving actually that at certain points they were resting on a single leg during running. These early films evolved to run at 24 Frames Per Second, which has been the standard for close to a century.

 

[Jarhead]

Oh, your eye can see extremely short flashes, trust me. It depends on how bright it is. A surface that is hit with light that is 1000 foot-Lamberts if it is on all the time is bright. A surface that is hit with the 1000 foot-Lamberts, but with an on time of 1/10th of the time, but repeats at 300 Hz averages in your eye to about 100 foot-Lamberts equivalent.

In the lab I've noticed that extremely bright flashes of very narrow duty cycles can be seen. But they look much dimmer than they really are.

From my experience, I'd say your eye is more like an analog instrument with an averaging filter applied.

I guarantee you that if I put up 200 different images at your 1/200th of a second "frame rate", you'd only "capture" a few, if any at all.

In testing of test pilots, I have noticed that the "frame rate" decreases with age. However you can train the eye to see anomalies that are byproducts of frame rates.

It also changes at different brightnesses as your eyes have rods and cones in them, and they react differently.

I can also say that folks can see a light source that has "no decay", such as phosphors, that is 70nS long, as long as it is bright. If I was to take this and take the reciprocal, it would indicate a frame rate of 14,285,714 Mhz, so that logic used by folks is totally bogus. If I take two LED dies that are smaller than a grain of sand and set them side by side, one green and one red, and flash them back and forth, green on red off, red on green off, at a 60Hz rate, they definitely appear a very solid yellow, yet my photodiodes with red and green filters on them show their light does not overlap. Now, if I zip my eye sideways, really fast, I see dots of red and green as the individual light hits different spots on my retina.

Oh, yeah, what do I do for a living? Heheh, I spend most of my time in a lab, developing things like this: http://www.upsat.com/mx20_gen.shtml