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White Paper - The Big Judder Problem and the Overhyping of 24p

post #1 of 146
Thread Starter 
Original is at: http://www.projectorcentral.com/judder_24p.htm

With the widespread availability of 120Hz and 240Hz LCDs and the limited availability of the 72Hz Pioneer plasmas, I thought this topic was appropriate for this Forum. Many people have 24p video sources attached to flat panels.

The Projector Central site is highly reccomended, I've made several purchases after doing research there.

The Big Judder Problem and the Overhyping of 24p

Evan Powell, November 11, 2008

Your brand new 1080p home theater rig is finally installed and ready to go. You're all set to sit back and watch your favorite classic, Casablanca, like you've never seen it before, with stunning clarity and contrast. Your Blu-ray player outputs 1080p/24, the signal format everyone is raving about. You've got the Blu-ray edition of Casablanca. Your 1080p projector displays the Blu-ray signal in native 24 fps format--everything is as pure and pristine as it can get.

So, you hit the play button. The Warner Bros logo splashes onto the screen. The globe rotates slowly. The map of the Mediterranean is rendered in breathtaking sharp detail. You smile in deep satisfaction with your new system. And then it happens. At two minutes and 3 seconds into the film, the camera holds the skyline for a moment, then pans slowly down to street level. You recoil in horror as the picture comes completely unhinged. It stutters and shakes like a delirious madman. The buildings are seemingly in the throes of a bizarre earthquake. It hurts to watch it. You blink repeatedly in disbelief. How could your brand new state-of-the-art 1080p projection system with pure, native 24p transmission come so dramatically unglued?

Welcome to 24p. What you just experienced was motion judder, an extremely annoying artifact that derives from the fact that movies are filmed at 24 frames per second (fps). The 24 fps sampling rate was adopted as a de facto standard in 1926 when the budding film industry recognized they needed a sampling rate fast enough to support a coherent audio track. (The first talkie, The Jazz Singer, was released in 1927). Prior to audio-enabled movies, they were filmed at even slower speeds, in part to save film, and in part because film exposure speeds were a lot slower back then.

The industry standard 24 fps film rate is an albatross that we've been stuck with ever since. As it turns out, it is way too slow to resolve camera panning motion cleanly. So when a movie camera pans at an unfortunate speed, you get motion judder. Sometimes you get it in spades. The sad fact is, your high resolution 1080p/24 system is simply showing you the picture as encoded on the Blu-ray disc in its authentic naked form. We just never saw it in our homes quite as naked before the advent of Blu-ray and HD DVD.

Actually, we've never seen 24 fps film quite this naked even in a commercial movie theater since the double shuttering action of the movie theater's projection system reduces the experience of judder and flicker. You can see some judder in the movie theater, but it is not as pronounced as it is on a digital home theater projector playing Blu-ray or HD DVD at 24p.

But wait, wait, wait, you say...... "I thought these judder problems were related to this 3:2 pulldown thing, and once we went to 24p, we'd have a clean picture." Well, a lot of people anticipated that, because all we've seen in the NTSC world until recently is 24 fps film converted to 30 fps display. That conversion from 24 fps to 30 fps (typically referred to as 3:2 pulldown) does indeed introduce a slightly different kind of judder, as well as some blur, when the camera pans. So it is perfectly natural to assume that a native signal that hasn't been compromised by this nasty 3:2 pulldown conversion process would look better.

As it turns out, the opposite is often the case. The motion judder in native 24p can be atrocious. You can test it yourself if you have the equipment to do it. We'll assume that if you have a Blu-ray player, you are more likely to have a copy of Casino Royale than Casablanca. If you do, find a messy panning scene in Casino Royale. There are lots of them, but there's a real beauty in the 9th chapter, starting at 1 hour, 11 minutes and 13 seconds. The dealer is dealing, and the camera pans slowly around the table.

In 24p playback, this scene is a pure, unmitigated disaster. The people seated at the table come apart at the seams, the tuxes flash and strobe, the Casino Royale logo on the card table blinks like a neon sign. Once you've replayed this travesty a few times, switch your Blu-ray player to 60p output and run it again. Yes, it is still a mess. But look at it closely ... the juddering effect is actually reduced. That is because the 3:2 pulldown is blurring and masking some of the latent motion judder in the film. There is certainly a separate conversion judder that is added to the visual stew with 3:2 pulldown, but oddly enough it works in contravention of the latent 24p judder. The net effect is that the image is a bit blurred, and the overall judder is noticeably reduced. Scenes like this do not look great in 60p, but they look worse in 24p. After all the hype over 24p (the benefits of which we eagerly anticipated as much as anyone), it must be admitted that 60p playback can, in the final analysis, be less distracting for many people.

Having been told that 3:2 pulldown judder is the scourge of humanity, it may be shocking to hear that it is not the worst fate that can befall the home theater enthusiast. But the fact is, the antiquated 24 frames per second sampling rate is the more onerous problem. And this is no secret. Professional cinematographers are acutely aware of the limitations of 24 fps capture rates. They go to great lengths to control the camera in such a way that juddering effects are minimized, because directors don't like it any more than we do. One common technique is to put the camera on a track and move the camera at the same pace as a moving subject, so that the subject remains stationary in the frame. If the subject does not move across the screen, the subject does not judder. However, if the background is moving behind the subject, the background will indeed judder.

If you've still got your Casino Royale disc in the Blu-ray player, you can see a good example of this. Go to chapter 9 again, and to 1 hour, 9 min, 6 seconds. Here Bond is walking through the hotel. Notice that the cinematographer places Bond in the right half of the frame, and the camera retreats as Bond approaches to keep him in a stationary position while the background pans. Bond turns to his right, and the cinematographer continues to hold him in the right half of the frame. When this scene is played in 24p, Bond remains stable and in focus while the background judders like crazy. When you play it back in 60p, the juddering effect in the background is still there, but it is reduced--it is easier to live with.

Notice further that the background in this scene is somewhat out of focus. In situations like this, cinematographers can use larger apertures to minimize the camera's optical depth of field. By doing so, they can focus on the foreground subject and intentionally throw the background out of focus. This causes the motion judder in the background to become less apparent to the viewer. In this particular scene they did not fully accomplish the objective, but it helps.

Therefore, there are two basic conclusions we can draw. First, motion judder is a natural byproduct of the 24 fps film rate. You will see it if you play a Blu-ray or HD DVD movie in native 24p transmission. How much of it you see will be directly related to how much moderate speed camera panning there is in the movie. Second, 3:2 pulldown conversions are a secondary source of judder. However, they tend to blur and soften the more aggressive instances of motion judder that you'd see in native 24p display. Leaving conventional wisdom aside, if you have the option to play your Blu-ray movies in either 24p or 60p, don't be surprised if you prefer the relative stability of 60p.

So, is there any way to get rid of judder?

Absolutely. One solution to the problem is called frame interpolation. But before we get to that, let's get clear on the root problem: the reason the picture judders when the camera pans is because the standard sampling rate of 24 frames per second is not fast enough to fully resolve the motion. If we captured movies at 60 fps and played them back at 60p, juddering artifacts would be pretty much nonexistent.

Frame interpolation is a process by which the projector (or video processor) approximates what a film would have looked like if it had been captured at a much faster sampling rate to begin with. What it does it this: It buffers two or more sequential frames of the film, and evaluates the motion shifts between them. Then it uses this information to create interim frames that are partial steps in the motion sequence between each real frame. For example, the Panasonic AE3000's "Frame Creation" system will look at either two or three prior frames (depending on the mode you select), and create three interim frames that are each 25% incremental steps in the motion between two real frames. These are fed out at the rate of 96 Hz each. So in reality, in each 1/24 second, what you are actually seeing on the screen is one original frame from the Blu-ray disc, and three subsequent "motion adjusted" interim frames, all four of which are being displayed in sequence at 96 Hz. To put it another way, when using the AE3000's Frame Creation mode, a total of 75% of the image information on the screen is not on the Blu-ray disc at all, but rather is being created by the projector!

The result is this: When you watch Casablanca, and you get to the point where the camera pans down from the skyline to street level, the picture is smooth, stable, and clear with no hint of motion judder. After seeing conventional 24p playback side by side with this, it is no contest. One delivers a visual nightmare, the other gives you a smooth, clear image.

Panasonic is not the only vendor to have included frame interpolation on its home theater projectors this fall. Several others will have it also. These include the Sanyo PLV-Z3000, and several of the Epson home theater models. Each vendor has a different implementation of frame interpolation. But they all address the basic problem of film judder by creating interim frames that represent small steps in the motion sequence. One way or another, they will enable you to experience the film pretty much as if it had been captured at 60 fps to begin with.

As a caveat, we should point out that frame interpolation is a brand new feature on home theater projectors. As such, it might introduce artifacts of its own until the wrinkles are ironed out. The only model we've seen to date with this feature is the Panasonic AE3000, and we have not seen any artifacts that could be attributed to the Frame Creation system. However, frame interpolation does increase video delay on the AE3000, and we expect it will do so on every model. So users will want to incorporate an audio delay into the system in order to resolve lip-synch issues.

Now, before we conclude, it is important to acknowledge that many videophiles today prefer the judder of the 24 fps film experience. To some film buffs, tampering with the natural judder is a sin, because it just doesn't look like authentic film if it lacks the inherent instability of the low sampling rate. And indeed, they are right, it doesn't. Frame interpolation techniques can make the picture look too clear, too stable, to the point that it can be unnerving if you are not used to it. (For this reason, the AE3000 gives it to you as an option, and you can turn it on or off as you see fit.)

But think about this. Back in the early days of silent films, there was no standard frame exposure rate. The cinematographer manually turned the crank on the camera and exposed film at anywhere from 12 to 24 frames per second or more. The ideal goal of the professional projectionist in a movie theater was to play back that film at the rate at which it had been exposed, in order to make motion look natural. But all too often, theater management wanted it played back faster than it had been exposed. After all, time was money, even back then. And truth be known, some of those films did in fact have better entertainment value when they were showed at modestly accelerated projection speeds. Artificially rapid motion was an aesthetic that many movie viewers came to enjoy. Sometimes, when action and comedy movies were projected at the rate they were filmed, people would complain that they were too slow. Romantic films, on the other hand, looked absurd when played back faster than the rate they were filmed. But the point is that people back then had their own ideas about what film should look like.

Today, the 24p sampling rate defines our own aesthetic reality about what a film should look like, judder and all. However, we are in a period of rapid technological transformation. Someday, in the not too distant future, films will be made at 60 fps. The generations to follow us will experience films captured at 60 fps as the aesthetic norm. They will be accustomed to the crystal clear motion that high resolution 60 fps capture will deliver (and that frame interpolation can give us a glimpse of today). When they look back at the 20th century and early 21st century films produced in the old 24 fps format, they will think it quaint that we could have lived with the juddering limitations of our technology. That is worth bearing in mind as we think back with bemused nostalgia on the era of the silent films.
post #2 of 146
Quote:
Originally Posted by Gary McCoy View Post

Original is at: http://www.projectorcentral.com/judder_24p.htm





So, you hit the play button. The Warner Bros logo splashes onto the screen. The globe rotates slowly. The map of the Mediterranean is rendered in breathtaking sharp detail. You smile in deep satisfaction with your new system. And then it happens. At two minutes and 3 seconds into the film, the camera holds the skyline for a moment, then pans slowly down to street level. You recoil in horror as the picture comes completely unhinged. It stutters and shakes like a delirious madman. The buildings are seemingly in the throes of a bizarre earthquake. It hurts to watch it. You blink repeatedly in disbelief. How could your brand new state-of-the-art 1080p projection system with pure, native 24p transmission come so dramatically unglued?

I swear, it's statements like this and several others that I have seen in this forum one would come to the conclusion that today's TV's are basically unwatchable. Now maybe it's different with a projection system (the few I've seen are very watchable and extremely nice in the proper environment) but my TV's and several others that I have seen put out an excellent picture and one with very little complaint. I just don't understand why so many people in this forum concentrate so much on minor flaws and blowing them up into enormous issues. If one set has a problem you don't like there is one out there that should satisfy anyone.
post #3 of 146
Thread Starter 
Perhaps you should read the entire article for the context of the paragraph above. The problem described above refers to playback of a native 24Hz video source on a display that does not refresh at 60Hz. There is further discussion about how the motion judder and blur introduced by the Telecine process can partially obscure the problem on a 60Hz display. If you don't use any 24Hz sources, you won't necessarily have as acute a problem as is described.

In my case, if I turn off my Samsung's frame interpolation, I can see a lot of 24Hz judder in camera pans. The problem description is accurate and it IS a significant quality issue.
post #4 of 146
Quote:
Originally Posted by Gary McCoy View Post

Perhaps you should read the entire article for the context of the paragraph above. The problem described above refers to playback of a native 24Hz video source on a display that does not refresh at 60Hz. There is further discussion about how the motion judder and blur introduced by the Telecine process can partially obscure the problem on a 60Hz display. If you don't use any 24Hz sources, you won't necessarily have as acute a problem as is described.

In my case, if I turn off my Samsung's frame interpolation, I can see a lot of 24Hz judder in camera pans. The problem description is accurate and it IS a significant quality issue.

Thanks for the advice Gary, but I did. It appears you missed my point.
post #5 of 146
Thread Starter 
Oh, I got your point, all right. Just out of curiousity, do you have any video sources set for 24Hz output?. What sort of TV are you not having a problem on?
post #6 of 146
Quote:
Originally Posted by Gary McCoy View Post

Oh, I got your point, all right. Just out of curiousity, do you have any video sources set for 24Hz output?. What sort of TV are you not having a problem on?

Just out of curiousity, what do you think my point was?

and yes, I have a PS3 set to 1080p/24 connected to a Pioneer Plasma but not sure what that has to do with my point.
post #7 of 146
Quote:
Originally Posted by maxdog03 View Post

I swear, it's statements like this and several others that I have seen in this forum one would come to the conclusion that today's TV's are basically unwatchable. Now maybe it's different with a projection system (the few I've seen are very watchable and extremely nice in the proper environment) but my TV's and several others that I have seen put out an excellent picture and one with very little complaint. I just don't understand why so many people in this forum concentrate so much on minor flaws and blowing them up into enormous issues. If one set has a problem you don't like there is one out there that should satisfy anyone.

I agree.
I will admit, judder can be a pain in some situations, but its nowhere near that bad.
If it were, then I don't think so many people would enjoys so many movies at 24fps.

If the actual cameras were filming at a better frame rate, this would improve things.
But IMHO, motion enhansing and interpolation is not the answer. too many downsides to all of the processing and adding of frames that weren't in the content to begin with.

If the original content had the extra frames, then thats a good thing I think.

Alot of us that watch movies in 24fps are not against filming in a higher frame rate, We are just against filming at 24fps, and then allowing enhansers to artifically add frames that werent there to begin with.

If the movie studios/Directors decide to start filming at higher frame rates, then thats fine with me.
But as long as they continue to film at 24fps, I will not allow artificial enhansers to mess with the original content.
post #8 of 146
I actually thought that article was really interesting - informative and accessible, well written. Really liked the history lesson, too. But I have what may be a stupid question: If cinematographers shoot digitally, is that still "film"? Does digital cinematography even have frame rates, like 24 or 60? I know theaters have to be upgraded to present digital movies, but does that imply that judder might be a moot point later on? I hardly ever go to the movies anymore so I'm really curious. (I guess I could Google it but I'd like to see some opinions here.)
post #9 of 146
Thread Starter 
Yes, digital video has frame capture rates. Both 30fps and 60fps are in common use - 30fps is especially suited to 480i60 or 1080i60 broadcasts since it allows you to broadcast the odd and even interlaced fields from the same source frame and avoid interlace artifacts. If you shoot at 60fps, you get better motion resolution for 720p60 broadcasts, but if that same source must be broadcast as an interlaced signal, you end up dropping half the available source fields and interlace artifacts abound.

However, most often when movies are made using video cameras, they most often shoot at 24fps. They do this so that vanilla 35mm distribution prints can be made from the video master, as film projectors far outnumber video projectors. But few new film projectors are being installed, and theaters are migrating to video at a faster rate - as time passes, the installed base tips towards video from film. Once video projectors comprise the majority of commercial theaters, faster frame rates can be used.

maxdog03, I understood your assertion that judder was not a significant problem. I am now trying to understand how much judder you are tolerating. So you view Blu-Rays off a PS3 at 1080p24 - so do I. Do you run your plasma at 60hz or 72hz, and do you use the Smooth Cinema option (if you have one on that display)?

In other words, I'm trying to determine if your playback system obscures the motion judder or presents it at full intensity.
post #10 of 146
Quote:
Originally Posted by Gary McCoy View Post

Yes, digital video has frame capture rates. Both 30fps and 60fps are in common use - 30fps is especially suited to 480i60 or 1080i60 broadcasts since it allows you to broadcast the odd and even interlaced fields from the same source frame and avoid interlace artifacts. If you shoot at 60fps, you get better motion resolution for 720p60 broadcasts, but if that same source must be broadcast as an interlaced signal, you end up dropping half the available source fields and interlace artifacts abound.

However, most often when movies are made using video cameras, they most often shoot at 24fps. They do this so that vanilla 35mm distribution prints can be made from the video master, as film projectors far outnumber video projectors. But few new film projectors are being installed, and theaters are migrating to video at a faster rate - as time passes, the installed base tips towards video from film. Once video projectors comprise the majority of commercial theaters, faster frame rates can be used.

maxdog03, I understood your assertion that judder was not a significant problem. I am now trying to understand how much judder you are tolerating. So you view Blu-Rays off a PS3 at 1080p24 - so do I. Do you run your plasma at 60hz or 72hz, and do you use the Smooth Cinema option (if you have one on that display)?

In other words, I'm trying to determine if your playback system obscures the motion judder or presents it at full intensity.

I watch my blurays on my ps3 and use advanced purecinema mode (72hz).
I really don't have an issue with judder unless its a particular scene with a really intense camera pan.
I know I could smoothen out the motion even in that situation by switching to smooth mode and let it interpolate, but it just reminds me too much of my sammy 71F or my XBr4. I like smooth motion, but theres a point where I have to say that its just too smooth and like live video.
post #11 of 146
interesting how the author prefers 3:2 over native 24 -
i mean your adding un-symmetric judder on top of sample-and-hold judder.
(i assume these native 24 projectors are basically sample and hold?)

ah well his main point was they both suck with motion - gotta raise frame rates IF you wanna avoid that stuff.
there ain't no other way afaik.
post #12 of 146
I read this when it came out and reread just now my thoughts have not changed.

If you have ever seen 24fps (pure no rate conversion) it will be a judder mess (as the article points out)

No movie theater that I know of shows a movie at 24fps they double flash and some triple flash (2:2-48 and 3:3-72 respectively) and you are left with film judder (the "film look" article make mention of this)

Most (if not all) FPs do not display 24 as 24 but do a 2:2-48 (Panny) 3:3-72 (Pio) just like the movie theaters, many LCDs do 5:5-120. So unless you think movies in the theater are some how unwatchable you should be fine.

If you think that the "film look" or "directors intent" are not important I would suggest you read the many threads on the matter

It's also strange that he prefers 3:2 as now you still have film judder but also have telecine judder. He claims he likes it better because it blurs the image and see I thought we all trying to get rid of blur
post #13 of 146
The answer to this is to buy a V series Panasonic plasma that refreshes at 96 because as everyone knows LCD and bad interpolation currently employed by LCD simply sucks!
post #14 of 146
yea the great thing about these lcd/plasma debates is they spice up any thread.
like pesto it goes with everything.....dinner a little too normal? smoother it with pesto.

...but then it tastes just like pesto...

there is nothing i would not smoother pesto all over
post #15 of 146
Quote:
Originally Posted by chadmak09 View Post

Does anyone know if there are any studios/directors who are/or plan on using higer frame rate cameras?
To me, this seems like a better alternative than letting the TV add frames that weren't already there.

The projectors at movie theaters already add frames by either double or triple flashing the frame. So directors already anticipate adding frames in what was once their primary market of Theaters. Theaters add frames where they weren't already
post #16 of 146
Quote:
Originally Posted by tombaker View Post

I am not baffled by why videophiles are talking about the cutting edge of technology.

i'm not either... yakking about cutting edge technology is what we do...

what i AM baffled by is the "what is the point of the white paper?"... it should come as no surprise to anyone that if something is presented in it's native 24 fps rate (without frame multiplying) that it's going to be a total disaster... the "cynic" in me thinks that he's making an argument for frame interpolation for more than "academic" reasons...

the author of the paper appears to be trying to make a point that really isn't relevant... he is being disingenuous by ignoring the fact that no one would actually watch "straight" 24fps (i.e. 1:1, instead of 3:3, etc.)... this paper appears to be a good example of "picking the facts that illustrate your point, while conveniently ignoring the rest of the facts"... imo, a poorly constructed paper...

i'm not surprised he prefers 3:2 over 24fps (presented natively)... i'd be shocked if anyone didn't...

as far as "when will we see 'faster' frame rates"? i don't think i'd hold my breath...
post #17 of 146
Quote:
Originally Posted by ccotenj View Post

i'm not either... yakking about cutting edge technology is what we do...

what i AM baffled by is the "what is the point of the white paper?"... it should come as no surprise to anyone that if something is presented in it's native 24 fps rate (without frame multiplying) that it's going to be a total disaster... the "cynic" in me thinks that he's making an argument for frame interpolation for more than "academic" reasons...

the author of the paper appears to be trying to make a point that really isn't relevant... he is being disingenuous by ignoring the fact that no one would actually watch "straight" 24fps (i.e. 1:1, instead of 3:3, etc.)... this paper appears to be a good example of "picking the facts that illustrate your point, while conveniently ignoring the rest of the facts"... imo, a poorly constructed paper...

i'm not surprised he prefers 3:2 over 24fps (presented natively)... i'd be shocked if anyone didn't...

as far as "when will we see 'faster' frame rates"? i don't think i'd hold my breath...

Agreed

I find the "paper" kind of ignorant or he was just trying to make some weird point. As this was written last Nov and he seems excited about the one projector that does interpolation, he must not pay to much attention to what goes on in the AV world in general as FP where on their second gen by then and had already been discussed to death.
post #18 of 146
Quote:
Originally Posted by Gary McCoy View Post

Original is at: http://www.projectorcentral.com/judder_24p.htm

With the widespread availability of 120Hz and 240Hz LCDs and the limited availability of the 72Hz Pioneer plasmas, I thought this topic was appropriate for this Forum. Many people have 24p video sources attached to flat panels.


Your brand new 1080p home theater rig is finally installed and ready to go. You're all set to sit back and watch your favorite classic, Casablanca, like you've never seen it before, with stunning clarity and contrast. Your Blu-ray player outputs 1080p/24, the signal format everyone is raving about. You've got the Blu-ray edition of Casablanca. Your 1080p projector displays the Blu-ray signal in native 24 fps format--everything is as pure and pristine as it can get.

So, you hit the play button. The Warner Bros logo splashes onto the screen. The globe rotates slowly. The map of the Mediterranean is rendered in breathtaking sharp detail. You smile in deep satisfaction with your new system. And then it happens. At two minutes and 3 seconds into the film, the camera holds the skyline for a moment, then pans slowly down to street level. You recoil in horror as the picture comes completely unhinged. It stutters and shakes like a delirious madman. The buildings are seemingly in the throes of a bizarre earthquake. It hurts to watch it. You blink repeatedly in disbelief. How could your brand new state-of-the-art 1080p projection system with pure, native 24p transmission come so dramatically unglued?

Welcome to 24p. What you just experienced was motion judder, an extremely annoying artifact that derives from the fact that movies are filmed at 24 frames per second (fps). The 24 fps sampling rate was adopted as a de facto standard in 1926 when the budding film industry recognized they needed a sampling rate fast enough to support a coherent audio track. (The first talkie, The Jazz Singer, was released in 1927). Prior to audio-enabled movies, they were filmed at even slower speeds, in part to save film, and in part because film exposure speeds were a lot slower back then. .

Can I spell it?

D-R-A-M-A!!

No, seriously, the description you post makes it sounds like noone's ever seen 24p judder before! Come on, man. That description is so overblown and melodramatic. It's creating a problem that, lo and behold, the writer is allowed to introduce 120Hz/AMP as a saviour to it.

It reminds me of that new infomercial for the toothpaste dispenser where, to make it seem like a necessity, they have to go overboard in making it look as though using a regular toothpaste tube is a fool's errand. (Or worse, that the operator must be some at the very least mildly retarded and unable to make such a complicated machine work!)

I call BS on that premise and this one as well.

I can live with 24p judder on my Pro-111 (such as it is), and don't need nor want AMP.

Now, with that all said (hopefully with a degree of tongue-in-cheek humor), I will say this: If camera-makers for film can create a camera that would allow smoother panning and no judder (all while allowing for natural movement - not the fast-forward effect of AMP), then I'll be first in line! But,. it's got to look natural.
post #19 of 146
Quote:
Originally Posted by tombaker View Post

The projectors at movie theaters already add frames by either double or triple flashing the frame. So directors already anticipate adding frames in what was once their primary market of Theaters. Theaters add frames where they weren't already

Thearters don't really add frames that where not there (no new infomation) it's still 24fps (why you have film judder), they just change the flicker-rate (refresh-rate).
post #20 of 146
Thread Starter 
I can think of a few high frame rate commercial ventures, none of which has succeeded in replacing vanilla 35mm film, even though each has succeeded from a technical perspective.

Todd-AO was introduced in the 1950's and two movies (the musical Oklahoma! and Around the World in 80 Days) were both shot on 65mm film stock at 30fps which was then used to prepare a 70mm distribution print at 30fps with six high fidelity magnetic sound channels. Subsequent Todd-AO productions (about a dozen and a half) were photographed at 24fps to facilitate distribution of Cinemascope prints.

IMAX HD simulator rides are popular at theme parks such as Great America. These have bumped the normal IMAX cinematic frame rate of 24fps up to 48fps for greater realism in a deliberate attempt to obscure the film photography. I experienced this on a ride called Soarin' Over California in the IMAX dome theater in the Santa Clara Great America. However there are no theatrical IMAX films shot at 48fps. In a shorter simulator ride the fact that each reel lasts half as long does not matter. However IMAX photography is 3-5 times as expensive even at 24fps, and 48fps costs more - doubling the amount of film and processing. It does however produce enough realism that the simulator rides come with motion sickness bags that not infrequently get used.

Maxivision 48 and Super Dimension 70 are 48fps adaptions of standard 35mm and 70mm distribution prints, and their inventors created retrofit kits for standard 24fps projectors in both formats. Both were released in 1999 and have been installed in such small numbers that (although I hate to jinx them by saying so) it appears that they will not be commercial successes. The prints are twice as long and more than twice as expensive, and to take full advantage of the higher frame rates you must also photograph at 48fps, which is doable on standard 35mm and 65mm film cameras (because higher frame rates are already in use for slow motion effects) but each raw film cassette only lasts half as long, limiting the length of a scene.

The Digital Cinema Initiative allows for frame rates up to 60fps in DCI 2K cinema, but as I mentioned before 24fps is typically used for easier compatibility with 35mm film prints. Still, when higher frame rates do come along, I believe that digital movie photography will be the source of such movies, as the DCI standard already allows for such, and the only downside is the greater storage space required on the Dolby Servers - but hard disks are cheap today.

Edit: Since November of 2008 several more digital home theater projectors with frame interpolation and faster frame rates have become available, the White Paper was written after the first such.

Edit #2: borf, dinner last night was grilled chicken breast with pesto and sun-dried tomato sauces (both) and provolone cheese on fresh ciabatta bread. If you have the ingrediants at hand, it only takes a few minutes on the George Foreman grill.
post #21 of 146
Quote:
Originally Posted by chadmak09 View Post

I for one am interested in hearing more about the possibility of filming at higher frame rates.

So could yourself and the other post above your please try and stick to the topic instead of adding fuel to a technology debate.

Your posting critisizms and telling everyone which members you "are tired of" is not helpful in staying on topic.

Does anyone know if there are any studios/directors who are/or plan on using higer frame rate cameras?
To me, this seems like a better alternative than letting the TV add frames that weren't already there.

wow quite a turn around from your previous posts on this subject. but in case your level headed plea is sincere...

member wwd mentioned the revolutionary Redone digital camera with a link to productions which i guess you missed a while ago.
i don't think you want higher frame rates as they give the soap look which you hate chadmack.
as director mike brennen puts it..

Quote:
In my view the judder effect of progressive capture at 1/48thsec shutter is the single most obvious technical factor for an audience that distinguishes film from interlace video. To put a figure on it I'd say 85% of the difference between film and video is bridged by using progressive capture.

-talking about 24p vs 60i

interpolation is a red herring imo - you cant blame soap on interpolation or interpolation artifacts, its about frame rate presentation (as seen in.....real soaps)
post #22 of 146
Quote:
Originally Posted by Gary McCoy View Post

... In my case, if I turn off my Samsung's frame interpolation, I can see a lot of 24Hz judder in camera pans. The problem description is accurate and it IS a significant quality issue.


The "judder" you describe is nothing more than the actual 24 Hz frame rate of the film itself. Of course the motion is not going to be infinitely smooth! You would see exactly the same thing in a movie theater!
post #23 of 146
This is very interesting, but I feel the real solution is higher frame rates, not interpolation.

In the meantime, a better stop gap would be for the studios to do the interpolation to a set standard like 120hz or 72hz, that way they could edit out most of the artifacts and the price of TVs would come down as they become simple display devices that display exactly what is fed to them.

I don't know the feasibility, but those are my thoughts.
post #24 of 146
Thread Starter 
I believe that frame interpolation is always going to be a beneficial feature because of the massive number of movies already captured on 24fps film. The shortcomings of the too-slow frame rate are all too apparent on today's high quality video displays.

All of us who are 30 years old or more grew up watching direct-view CRT televisions complete with Telecine judder because most of the source material was film. I believe that this has resulted in an insensitivity to 3:2 judder which has now carried over to the 60Hz HDTV display - it's more visible on the HD display of course, but it has the comforting look of the 480i broadcast. It does bug me and I took steps to eliminate it from my home theater in 2003 by switching my projector between 60Hz and 72Hz depending upon the source material.

The 24Hz judder from 24fps film is something else that has always bugged me in a theater. I first noticed it in 1960 when my 8-year-old self was being terrified by the giant spider with a monkey face in the SF "B" movie The Angry Red Planet. There was a problem with the spider's movement on screen, and it went beyond the stop-motion animation in use in the film, because the same problem could be seen in the actor's movements.

To me in particular, the 120Hz Samsung with AMP finally brought blessed relief for this problem. Higher source frame rates will also be appreciated, but I have already been waiting for such for almost 50 years.
post #25 of 146
I was about to ask why "double" or "triple" shuttering film projection in theaters would affect the fundamental 24fps temporal visual artifacts but tower101 already addressed that issue. It's still 24fps with a 48Hz or 72Hz refresh rate. I wonder if any scientific human visual perception studies have been done to examine the effects of that higher refresh rate?

In any case, the other major question I had on the 24fps issue was the concept of certain video processors (either stand-alone or integrated into a TV/Monitor or player) performing active multi-frame scene analysis in order to compute "interpolated" frames. Leaving aside the questions of whether it would be better to film at higher fps rates or have the original film studios master this modified content, is there a list available for current devices which do this? (Oh, and by the way, is this the "soap effect" I've seen referred to here?)

For instance, I've ordered a Pioneer KRP-600M and in searching the forums and reading the manual I see a capability referred to as "Pure Cinema" which can be "off", "standard", "smooth" or "advance". It appears from the manual that "advance" does the "triple shuttering" referred to above. The "smooth" mode might be some form of inter-frame interpolation but it's not clear from the manual.

Just curious. No torches. No grand mission. Basically stupid as a post and trying to get educated.

Casey
post #26 of 146
Quote:
Originally Posted by Gary McCoy View Post

The 24Hz judder from 24fps film is something else that has always bugged me in a theater. I first noticed it in 1960 when my 8-year-old self was being terrified by the giant spider with a monkey face in the SF "B" movie The Angry Red Planet. There was a problem with the spider's movement on screen, and it went beyond the stop-motion animation in use in the film, because the same problem could be seen in the actor's movements.

While I find your postings exceptionally interesting and thought provoking I don't really buy the part with the eight year old cinephile!

bye
Benny42
post #27 of 146
The article did present known facts and some useful info, but its hyperbole turned me off. It was not necessary as the lead up into frame interpolation. Once 1080p became common place, "people" needed something else as a "must have", and that was 1080p24. And the only reason why people jumped on the bandwagon was because, even though they didn't know what they were going to get, they knew they didn't have it.

larry
post #28 of 146
Quote:
Originally Posted by PooperScooper View Post

the only reason why people jumped on the bandwagon was because, even though they didn't know what they were going to get, they knew they didn't have it.

yes about 2 years ago when the first 120hz sets debuted people were demanding 5:5 from manufacturers (the "magic number" - 24 divides evenly into 120) -

nobody (except the engineers) figured telecine judder would give way to repeat frame judder lying underneath in addition to increasing sample-and-hold blur. substituting one problem for another is all that can happen with low fps.

post #29 of 146
If you don't want judder at 24p, you just have pan slower and open up the shutter angle. Blame the cinematographer if you see unacceptable strobing.

Flicker is a separate problem.
post #30 of 146
Quote:
Originally Posted by -Spiff- View Post

If you don't want judder at 24p, you just have pan slower and open up the shutter angle. Blame the cinematographer if you see unacceptable strobing.

Consequence: Even if you had 60p - if you pan fast enough you'll get judder, too?

bye
Benny42
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