120Hz and True 24p

So sony has it's line of televisions that have 120Hz and "True 24p" but I cannot seem to find another company that has both.

Samsung has 120Hz televisions without a True 24p mode.

What exactly is the deal? Is it ideal to have both?

I want my 1080p Blu-Rays looking their best.

Peace,
Tom Scholfield

Re: 120Hz and True 24p

Yeah, how about refresh rate too. Not many manufacturers list this spec either.

Re: 120Hz and True 24p

I thought 120Hz was the refresh rate?

And Sony has both 120Hz and True 24fps. At least my KDS-60A3000 does. It's either one or the other and you can enable/disable 120Hz. You have to disable it to get to true 24fps, assuming your source device outputs are true 24fps.

As far as "looking their best" - personally I don't like having 120Hz on. It makes the movie look, surreal is the only way I can describe it. If a movie was recorded on 24fps film (which most are), then you want your source device (Blu-ray player) outputting in 24fps and not adding/interpolating additional frames to get to 120Hz.

Re: 120Hz and True 24p

That doesn't sound like a simple 120Hz refresh rate though. If it's a simple 120Hz refresh rate, then it should be useable for true 24fps playback considering it's wholly divisible by 24, no? There should be no need for in-between frames extrapolation in that case -- just simply repeat each frame 4x more -- no?

_Man_

Re: 120Hz and True 24p

The problem is, depending on your settings, a 120 Hz display can make film look like... well, video. I was in a Sony Style store the other day where they were showing off their 120 Hz, and it was obvious they had all the enhancements cranked to the max. The clips from Spider-Man 3 and POTC on the demo disc looked like they originated on video. Frickin' weird, I tell ya.

Re: 120Hz and True 24p

That "video" look comes from the Judder elimination. Some people love it, some hate it (I hate it), most if not all sets should allow you to turn this off.

Re: 120Hz and True 24p

Is it really just judder elimination (by simply repeating frames equally) or more than that (by extrapolating in-between frames, not just repeating them)? I got the impression it was actually more than just repeating frames that cause the odd look problem -- and that it was mainly a trick to make LCDs look better than they normally do when there's motion involved.

_Man_

Re: 120Hz and True 24p

All I know is that every "120hz" TV option I've looked at, my Sony, Samsungs, LGs, Toshiba, give it that "unreality" look. It's *too smooth* if there can be such a thing. Hard to describe, easy to spot. I prefer it off.

Re: 120Hz and True 24p

I call it "live effect" or "soap opera effect". Either way, movies don't look right with it.

Re: 120Hz and True 24p

Personally I don't understand why the love for the judder. Rather than film like or video like, should'nt the objective be to try and achieve the closest to 'life like'. Why is the pursuit of the best in Cinema equated with FILM? 24 frames per second is a weakness of film, not it's strength. So why do we have to insist on the film like, with it's glorious judder, look? Basically the argument I am trying to make is, that the judder is not something that was aimed for but rather was na inherent weakness of film due to it's low frame rate. Thus should'nt we 'progress' and utilize what today's technology allows us to achieve?

Re: 120Hz and True 24p

I don't think it's a "love for judder". It's just that our eyes have grown accustomed to it so that we are used to it, and seeing otherwise really throws us off.

Think of it this way, your perception of color is based on how your eye and brain interpret things. [Ever wonder if your perception of "blue" looks like other peoples perception of it? How would you know?]

If suddenly your brain reversed your perceptions of blue and red, so that the sky was always looked red, well that's not necessarily wrong but it would look weird to you having had many years of seeing blue.

Also, I don't think the objective is to appear "life like" but to appear "true to the source." If it's filmed in 24fps film, that's the goal. If it's filmed in 72fps film, that's the goal. If it's filmed in 1080i/60 video, that's the goal.

Otherwise you start down a slippery slope, first with refresh rates to appear more "life like". Then brighten up movies like The Godfather to make it more "life like". Then remove the green from The Matrix to make it more "life like".

IMO, the goal should be to have the home theater presentation to be true to how it was filmed.

Re: 120Hz and True 24p

24fps is not a weakness of film. You don't think they could make films at higher frame rates if they wanted to? It's a deliberate choice to achieve a deliberate look.

Re: 120Hz and True 24p

I don't have much to add (other than I hate that super-smooth look as well) but I wanted to mention that I recall some Canadian TV shows looking like this, back in the 1990s. Never knew why that was, but for whatever reason I've always remembered that probably because I never got over how strange it looked.

Re: 120Hz and True 24p

Carlo, what you're describing is DEFINITELY frame interpolation, not just 24p. I installed a Panny AE3000 projector for a friend this week and we watched in 24p from his Panny BD35 BR player. It just had a nice, filmlike smoothness, not that unearthly oiliness that characterizes the frame-interpolated video I've seen in Best Buy.

Zack, 24fps was chosen at the beginning of the sound era because it was the lowest framerate that enabled reliable sound synchronization. (Silent films were largely shot at 16fps.) They wanted to keep the framerate as low as possible because faster framerates use more film stock which costs more money. It was more of a technical and financial choice than an aesthetic one.

However, the judder in home video is largely an artifact of 3:2 pulldown, not 24p. In 24p, you get some strobing, particularly with today's hyperactive action and fast cutting. When digital video replaces film as the feature film medium (and film stock costs go away), I sincerely hope they choose to increase the framerate because today's style of film making really would benefit by it.

Re: 120Hz and True 24p

Bob, it's irrelevant the genesis of 24fps, it's 80 years on and for most of that 24fps has been solely an artistic choice. Faster frame rates have been tried and experimented with in the past and abandoned, and there are plenty of examples where shooting faster would be easier and more economical, yet the choice is not made. In today's world of HD cameras and digital theaters it would be very easy to branch out into other frame rates, but I don't expect it to happen.

Re: 120Hz and True 24p

I'm not sure I agree with the "solely an artistic choice" part of all of this. The bottom line is, the higher the fps, the more film you'll use. It's simple economics. 24fps was most likely the best combination of good picture without breaking the bank. Remember if you use 30fps you'll use 25% more film. 48fps=100% more film. 72fps=200% more film. As much as directors (the "artist" making the artistic choices) have some say, studio economics and financial concerns tend to trump all (unless your name is Lucas, in which case you decide to shoot all HD during a time when it wasn't financially a popular choice). Even Hitch had to occasionally bow to studio pressures (read about his epic battles with Selznick). Ditto Coppola, Spielberg, Kubrick, etc.

However, back to the discussion at hand, no matter how you cut it, if 120hz is not how the source material was shown, I'm of the belief that you maintain, to the highest degree possible, how the original material was shot and intended to be displayed. Anything else is quite simply an alteration of the original source material.

Re: 120Hz and True 24p

There's certainly a status quo aspect to it by now Carlo, but like I said there are many examples of faster framerates being more desirable from an economical stance. A lot of television work would benefit more from the ease of shooting 30fps vs. the cost of film. For decades most all major releases got 70mm print releases, this too doubles the amount of film used but it was still practiced because studios want quality even if they are frugal.

Like I said earlier, today we have major films each year that are shot on HD video and released to thousands of DLP cinemas across the country, eliminating the cost of film entirely for their respective runs. Many television shows are shot with HD cameras now, at 24fps, only to be broadcast at 30fps. And even in the consumer markets, you have camcorders that for years shot at 30fps, but now the high end ones feature the ability to shoot 24fps.

It's not as if there aren't any obstacles at all to shooting faster, for example VFX work would ideally need to be rendered at faster frame rates as well. Just a few years ago this would have been very costly but today it's much less of an issue.

What it really comes down to IMO is what you expressed first hand Carlo, when talking about the judder issues with 120Hz TV sets. You just don't like the way it looks. Neither do I, and neither do a lot of people, and that's essentially the look you'll get when shooting at higher frame rates. Decades ago they experimented with 60fps filmmaking-- they found it made things too* real and made a lot of people sick.

Re: 120Hz and True 24p

The brain interpretation is the key. I agree with Carlo, keep it all as close to the way it was shot in the first place, that is "high fidelity". Anyone who truly loves and appreciates good sound is after hard to find vinyl. The CD is nice but the sound just is not the same and never images as well as real high end analog on a high end system. The MP3, a complete abomination to anyone with more than a tin ear! Yet, we have a whole new generation that thinks MP3 is great. I find it barely acceptable for portable sound and completely unacceptable unless you are almost legally deaf for true listening. The cheap way once again is rarely the best way............................

Re: 120Hz and True 24p

Sorry, Zack, that just wasn't the case. The big roadshow releases would get 70mm prints for major markets, but that was a small minority of film releases. (Remember, it isn't just an issue of striking prints. You also need theaters equipped to project 70mm.)


Studios want money. Widescreen processes and large format film technologies were adopted in the '50s to compete with television and give theaters something to sell that viewers couldn't get at home. That was also the motivation for 3D in 1951-53. And it appears we're currently revisiting that age-old motivation with IMAX and the major 3D features scheduled for release starting next year such as Cameron's "Avatar."

Television would possibly benefit from shooting in native 30fps but until HD, video wasn't up to achieving the necessary resolution quality and storage permanence of film.

I'm not aware of any fast framerate film processes that caused nausea. In the '50s ToddAO was shot 30fps and I don't think anyone was puking on their shoes. Cinerama upped its framerate to 26fps, but just to try to reduce flicker in that big enveloping screen. Natively-shot IMAX runs at 48fps without any apparent viewer stomach upset. And Doug Trumbull's Showscan process (which went bankrupt in 2002) was (is?) in place in several theme park applications running 70mm at 60fps and I don't think they have to mop the floors after each screening.

On the occasions when I saw Showscan at work (or native IMAX, for that matter), I didn't experience that weird motion quality caused by frame interpolation on some new video monitors. It just read, to my eyes, as an increased sense of realism, and it occurred at a subliminal level. Frankly, it looks more like a picture with increased detail, rather than a faster framerate (perhaps because the brain was actually getting more than twice as much information as it gets with 24fps.)

If content is shot at 24p (pr 29.97fps or 60fps), it's best to view it in its native framerate. However, I still contend that today's shooting styles would benefit from higher framerates and that there is nothing magical about 24fps (which, in any case, is always projected at 48fps to reduce issues related to persistence of vision). It's just what we're currently used to seeing. If you had an extended period of seeing only 48fps or 60fps content, you'd think 24fps looked somehow "odd" by comparison.

Re: 120Hz and True 24p

Although I am not sure I am totally convinced about sticking to everything as it was originally. I for one prefer the remixing of old audio tracks to 5.1 as long as they have the original audio stems to work with. But I do get your point and specially like your very interesting take on the issue regarding 'perceptions'.

Personally I think, that unlike the case with a 'specific look' that the director so many times intended, in most cases, 24p has been the standard simply because it is the 'standard'. As for why it is the 'standard', my guess is that it was the lowest number of frames required to create a visually convincing real life like look. The choice of 24p at the time, was simply a matter of economics and the reason for not too many movies being shot in 70MM, also is quite simply due to it's much higher cost and thus it was only the high budget movies that went in for 70MM. By the way the high cost of shooting in 70mm is not related to just the film stock, but even the cameras cost a lot more and then the fact that very few theaters worldwide are even equiped to project 70MM due to the high cost of projectors, screens etc. Why don't they switch to a higher frame rate now? Quite simply because of the exisitng hundreds of thousands of theater projection systems worldwide. Thus, even digital films shot now have to keep in mind the non digital theaters, which by the way still far outnumber the digital theaters by quite a margin. Maybe once the whole world has switched to digital, you might find that film makers actually start to prefer shooting in higher frame rates.

In the case of audio, ofcourse excluding the rare example of Woody Allen, mono sound was there only because of the lack of technology and when the technology did become available it was relegated to movies shot in 70MM which again brought in the cost issue.

Re: 120Hz and True 24p

This talk of frame rates is very interesting. I just keep coming back to the whole "looks like it was shot with a camcorder" thing. If movies start using higher frame rates as a standard in the future, it damn sure won't look like what's happening on these tvs with 120hz on. It's effect has degraded the image rather than improving upon it.

Re: 120Hz and True 24p

Man, we aren't going to have one of those stupid "the director would have shot it in full color 3D hologram in 12.1 surround sound if it existed in 1941, so I want Casablanca to be colorized 3D in 12.1 surround" threads? I thought this was the HTF?

By the way, the posters who said the frame interpolation feature is separate from the 120Hz feature are correct. The interpolation can be turned off (as it should be) and you can have just the 120Hz refresh rate (i.e. 24p x 5).

Re: 120Hz and True 24p

Which leads me to an interesting question. Without the frame interpolation (which I'll assume is what creates the "unreality" look to things), then what really is the difference between 120hz (24fps x 5 each frame) and 24fps?

I ask because what people are calling as judder (which may or may not be the right term for it) for 24fps sources is presumably the "missing data" between frames. i.e. each frame accounts for 1/24 of a second, and something in motion does something in the time between 24ths of a second. So we have something like this:

1 - 2 - 3 - 4 - 5

With the theory being the judder is the missing information between 1 and 2, 2 and 3, 3 and 4, and 4 and 5 right? Frame interpolation is meant to fill in that gap so you get something like (roughly):

1 - 1.5 - 2 - 2.5 - 3 - 3.5 - 4 - 4.5 - 5

With the ".5" parts being interpolated and filled in by the processor to give a "smoother" look to it all. That's the "unreality" part of it that bugs most of us.

However true 120Hz with no interpolation would yield this (at 5x the speed of 24fps):

1-1-1-1-1-2-2-2-2-2-3-3-3-3-3-4-4-4-4-4-5-5-5-5-5

So the in-between data, the ".5" are still missing. So what would be the visible benefit to this? Just curious.

Re: 120Hz and True 24p

The thing to realize is that since 120 is a multiple of 24, the actual fps will map exactly to the refresh rate:

1-1-1-1-1-2-2-2-2-2-3-3-3-3-3-4-4-4-4-4-5-5-5-5-5 @120Hz

This is in contrast to a 60Hz set, which will give you:

1-1-1-2-2-3-3-3-4-4-5-5-5-6-6 @ 60Hz

Since the 24fps maps exactly to the 120Hz refresh rate, the image is more representative of the actual film look than the 3:2 cadence needed to map 24fps to 60Hz. The benefit is not in the interpolation (Blech!), but in the superiority of a 120Hz display over the old 60Hz displays in displaying a true 24Hz film rate.

Re: 120Hz and True 24p

Agreed, if such displays actually allow this frame quintupling, instead of interpolation, at 120fps.

Also, depending on exactly how the display tech works out, running at higher frame rate like this can reduce the strobe effect. This should be the case for CRT-based displays, but I'm not sure about others like plasma, LCD, DLP, etc. since they don't have the same kind of image scanning issue.

BTW, I thought modern day theaters don't generally actually project at 24fps anymore, but at some multiple of 24fps for exactly that reason.

_Man_

Re: 120Hz and True 24p

Agreed on both counts above. I can see how 120hz being a multiple of 24 reduces the 3:2 pulldown effect on 60hz displays. But it shouldn't result in that look that frame interpolation gives, right? That stuff makes things look "hyper-real" or "unreal" in a way that simple 5x multiplier would do since effectively it's still 24fps of unique information, just shown 5x.

Re: 120Hz and True 24p

24 fps source to 120 Hz TV set -- Should display with 5-5 pulldown if no interpolation is included.

60 fps 3-2 pulldown source to 120 Hz TV set -- Should display with 5-5 pulldown if no interpolation is included although some models give you 6-4 pulldown. The latter means that all of the 3-2 pulldown judder is still there.

60 fps 720p or 30 fps 1080i to 120 Hz TV set -- Should display with 2-2 pulldown if no interpolation is included. Interlaced material needs to be de-interlaced and not have individual fields used twice in a row as 2-2 pulldown.

30 fps non-interlaced video -- Blu-Ray player will impart 2-2 pulldown and output as 720p, 1080i, or 1080p. 120 Hz TV should impart 2-2 pulldown again with the result being 4-4 pulldown relative to the source.

Re: 120Hz and True 24p

Thanks Allan, that made it very clear to me. So the effect we see on these displays is more the fault of a "tru-motion enhancement" rather than 120hz? That's what I originally thought was happening, but, wasn't sure.

Re: 120Hz and True 24p

There is a very interesting article on projectorcentral.com called, 'The Big Judder Problem and the Overhyping of 24p'.

Re: 120Hz and True 24p

Interesting discussion here. I happen to be in search of a new television and had been considering samsung's LCD line. I was looking at the series 6 46" because it had the 120Hz feature...and it was a considerable amount more for the series 6, whereas the line right under it only has 60hz, but is a bit more affordable by a couple hundred dollars.

Would it make more sense to deal with the 60Hz and pay less in order to afford a larger television...i.e. 52"?