At what framerate does movement become indistinguishable form reality?

[mzso]

Hello!

I'm wondering at what's the max framerate that's still perceivable. I didn't find something agreed upon on the net so far. Unlike for other things like audio frequency or contrast, etc

I assume it's dependent what's show, but there's bound to be an ultimate value.

[Sparktank]

I don't think there is an "ultimate" value.

It's more like 3D perception, in that everyone's eyes are different.
There would also be a lot of other factors.

Is it naturally filmed in higher frame rates or is it interpolated?
The lighting for each scene could cause a huge impact on the outcome.
Do you pay attention to detail like motion blur?

I've watched the first two Hobbit films in 48fps and did notice it was a surreal environment in 3D.
More so than a standard 24fps 3D movie.

Interpolated FPS is very different. The artefacts and ringing can stand out.
Although, using the "Pulfrich Effect", the artefacts/rining are slightly less noticable since you're viewing it differently.

I would imagine naturally filmed HFR would look closer to "reality".
60fps is a common frame rate for digital production (nothing commercial, at least Hollywood-wise; mostly independent short video projects; or just people with enough money to buy a camera that can record in HFR).

Gaming commnities talk about there being no real difference (to the common gamer; except maybe for a few Jedi Masters...) beyond 76~ fps.
Perceptually.

my monitor can only go as high as 75Hz for refresh rate.
Interpolating NTSC_FILM (23.976) to 60fps, I can see a difference. (using SVP)
Going to 75fps, I can really see a difference, but it's very messy, as I'm interpolating and none of it natural.

If I set a custom resolution to 72Hz and playback in normal FPS, it looks better.
Double frame rate looks even nicer as the monitor is much closer to a multiple of the original frame rate.
Interpolating beyond 60fps is still messy though, even if it is 3:1 interpolation. Unless, I drop resolution down to 800p.
Or convert before hand to a 480p resolution and then try interpolating.

I think each person would have to test to find what's more realistic for themselves.
For this, you would need naturally filmed HFR and a monitor with a refresh rate higher than 75Hz.
The difference between a 120/144/260 monitor with HFR content... Sounds like something fun to do.

Personally, the 48fps Hobbit films are fine for me.
Too bad there won't ever be a digital release of them for those who want them.
Even if I were to interpolate the BD's to double the frame rate, it's still not the same as the other frames dropped contain original data.

I would love to see natural 60fps content on a 120Hz monitor (heck, even just on my standard 60Hz monitor).
Or a 48fps film on a 144Hz monitor.

[vivan]

http://www.100fps.com/how_many_frames_can_humans_see.htm

[mzso]

http://www.100fps.com/how_many_frames_can_humans_see.htm

So the answer is no-one knows? :) (Although 500 seems a reasonable guess.)

[Bloax]

You shouldn't forget that light in the real world is an incredibly constant stream of information, instead of very frequent bursts as they are in monitors.
Which means that the framerate at which we see depends on how much light the receptors have to receive to perceive it as information, since otherwise it would depend solely on how close to infinity you want to come.

Generally, it all boils down to what kind of content you're watching - for slower things you probably won't have much benefit past 48 or 60 fps - but for really detailed and fast things (https://www.youtube.com/watch?v=h4adtE2_gC4) that number would be much higher.

[StainlessS]

To appreciate in its full glory at low frame rate, DONT BLINK.
If only we had those devices in "A Clockwork Orange", that keep your eyes open despite protestations,
I can hear Beet Oven even as I write this.

[Asmodian]

Motion Blur is a huge issue when talking about frame rates humans can see, at least given current "sample and hold" displays. Even 500 fps isn't fast enough to totally eliminate perceived motion blur, though it is pretty minimal at that point. 120 fps in video games is obviously smoother than 60 but the improvement in motion blur is even more significant in my opinion.

That 100fps.com link is very good, even if I wouldn't call Quake a modern game. ;)

[huhn]

this page is a little bit outdated: http://www.100fps.com/how_many_frames_can_humans_see.htm

it is so old I get the feeling they talk about CRT displays only and CRT displays still have the lowest motion blur to day. they simple doesn't have any motion blur problems at all.

today we got the problem of extra motion blur with our displays even a little bit with plasma screens.


I would love to see natural 60fps content on a 120Hz monitor (heck, even just on my standard 60Hz monitor).
Or a 48fps film on a 144Hz monitor.

120/144 hz monitor look strange without 120/144 hz input don't ask me why but I can easily see ghosting with low frame rate input.

to me 120 FPS are not a huge thing to me 60 looks totally fine most of the time. so I think we get pretty good motion with 60 FPS. it's not like I can't see a difference in high motion but it totally "WOW".

[Sparktank]

120/144 hz monitor look strange without 120/144 hz input don't ask me why but I can easily see ghosting with low frame rate input

That's interesting. I just thought it would be smoother being a multiple of 60/24 fps.

I do hear it works wonders for 3D, though.
I think largely 3D-gaming, that is.

I'll have to hit one of the stores and watch some demos one day.

[mzso]

this page is a little bit outdated: http://www.100fps.com/how_many_frames_can_humans_see.htm

it is so old I get the feeling they talk about CRT displays only and CRT displays still have the lowest motion blur to day. they simple doesn't have any motion blur problems at all.

today we got the problem of extra motion blur with our displays even a little bit with plasma screens.


There's something about that. Google first saw it in 2002-10-01 (https://www.google.com/search?safe=off&as_qdr=y15&q=100fps.com).

[huhn]

That's interesting. I just thought it would be smoother being a multiple of 60/24 fps.

I do hear it works wonders for 3D, though.
I think largely 3D-gaming, that is.

I'll have to hit one of the stores and watch some demos one day.

I talk about a true 120 fps screen no interpolation. there is no difference in smoothness with a 60 fps source each frame is just shown 2 vsync.

[2Bdecided]

There has been loads of work done on this in the last decade.

NHK demonstrated 60-vs-120-vs-240fps (the latter clearly wins by a large margin for eye-tracked motion), the BBC previously proposed 300fps but recently demonstrated 50-vs-100-vs-150fps, BT.2020 includes 120fps, ...

https://www.dvb.org/resources/public/scene/dvb-scene44.pdf
see page 7

http://www.bbc.co.uk/rd/publications/whitepaper209
http://www.bbc.co.uk/rd/publications/whitepaper169
http://www.bbc.co.uk/rd/publications/whitepaper282
http://www.bbc.co.uk/rd/publications/higher-frame-rates-for-future-tv-systems

That should keep you busy ;)

Cheers,
David.

[mzso]

There has been loads of work done on this in the last decade.

NHK demonstrated 60-vs-120-vs-240fps (the latter clearly wins by a large margin for eye-tracked motion), the BBC previously proposed 300fps but recently demonstrated 50-vs-100-vs-150fps, BT.2020 includes 120fps, ...

https://www.dvb.org/resources/public/scene/dvb-scene44.pdf
see page 7

http://www.bbc.co.uk/rd/publications/whitepaper209
http://www.bbc.co.uk/rd/publications/whitepaper169
http://www.bbc.co.uk/rd/publications/whitepaper282
http://www.bbc.co.uk/rd/publications/higher-frame-rates-for-future-tv-systems

That should keep you busy ;)

Cheers,
David.

Cool. I'll skim them.

[smok3]

300 fps seems like a nice choice, two things that got my attention;

- 1/300 shutter speed would need at least 6x amount of light (compared to classical 25fps at 1/50)
(example: steadycam shoot that I would like to shoot with 1/100 at f5 with 100iso would need at least 5000 lux of light on-face < even that is a challenge for a low-tech guy.)
- I can't spot a nice paper that would actually work on human eye and how to represent that in tech (Without just going crazy in fps area)

Enlighten me.

[wonkey_monkey]

- 1/300 shutter speed would need at least 6x amount of light

Would it? I'd have thought you could get away with higher noise in each frame if those frames are updated faster than before. It'd still be the same amount of data, in that sense - just with pixel value accuracy sacrificed for temporal resolution.

If you pause a grainy movie, you might see there's more grain in each frame than might be evident from watching it in motion.

With 300 frames a second to work with you could probably get a lot done with even strict motion-compensated noise reduction, too (which is kind of a side effect of broadcast compression, anyway)

[smok3]

@davidhorman, well you can always just use higher ISO, but that was not the point.

[mzso]

Okay, so "shutter" means BFI, right? It's less than obvious.


300 fps seems like a nice choice, two things that got my attention;

- 1/300 shutter speed would need at least 6x amount of light (compared to classical 25fps at 1/50)
(example: steadycam shoot that I would like to shoot with 1/100 at f5 with 100iso would need at least 5000 lux of light on-face < even that is a challenge for a low-tech guy.)
- I can't spot a nice paper that would actually work on human eye and how to represent that in tech (Without just going crazy in fps area)

Enlighten me.
Or at least six times more sensitive sensors. That's like 2.5x times the height/width.
Or better tech might come out wich is a lot more sensitive like black silicon sensors.

[Ghitulescu]

To appreciate in its full glory at low frame rate, DONT BLINK.
If only we had those devices in "A Clockwork Orange", that keep your eyes open despite protestations,
I can hear Beet Oven even as I write this.

You can use the cheap version as shown in "Conspiracy Theory (http://www.imdb.com/title/tt0118883/)", namely Magic Scotch Tape.

[StainlessS]

Arh, the ever magic Scotch tape, not though as magic as Scotch on the rocks.

For you film buffs, the prison appearing in "A Clockwork Orange", is Wandsworth nick, little more than a mile from me.
I thought I recognised some landmarks from the movie and fired up Google Earth, yep tis that correctional institution
that we all know and love (happy days, arrrh....).