Why 24 FPS? (1 Viewer)

[Joe Schwartz]

Although a film projector shows only 24 frames per second, the shutter causes each frame to flash twice. In effect, you see the film projected at 48 Hz, which tends to reduce the flickering sensation.

 

[Kevin M]

To be honest I know what you mean but I understand exactly what KylePete is referring to and in fact it has only been grossly noticeable to me while watching all of the LOTR films in a theater and noticing this "Shutter" during slow or fast pans and then observing later on that it isn't on the DVD's.
I too would like to see 30+ FPS or perhaps Douglas Trumble's format Showscan, if you have seen any of his movie rides then you know what 60+fps looks like on screen and to me it looked quite good and not at all "Video like"...YMMV.

 

[Dennis Pagoulatos]

A good example of the stuttering landscape effect is during the opening sequence of "Braveheart" when the camera is flying over the Scottish highlands. There's one particular shot where the camera is flying fast over a hillside, and the hillside is relatively close to the camera, and it stutters like crazy because of the fast pan that the camera is doing. As soon as the camera gets over the hill to reveal a huge shimmering valley in the distance (not much movement), the effect is gone. I always noticed this in the theater (saw it 3 times) and then again on my widescreen LD of the film (great DD5.1 track!), and on the DVD as well. I'm convinced it has to do with the limitations of film; static shots can look breathtaking, while fast, especially close-up motion usually looks less than good, and can look REALLY bad in certain circumstances.

-Dennis

 

[GregK]

The $5 question: Why does film * stay * at 24fps? Cinerama was 26fps, Todd-AO was 30fps, and Showscan was a whopping 60fps. These formats, Showscan in particular, greatly benifited from the increased frame rate.

But in their later forms, Todd-AO and Cinerama dropped their frame rate down to 24fps, to maintain compatibility with 24fps theaters, as most projectors worldwide are designed to run at only 24fps. Then there's the additional cost of more film from the initial shooting through to projection.

Minor cost increases and slight projector modifications aside, there's another reason for the 24fps freeze: It's been a common practice for a few generations now to shoot film at 24fps (even for most TV shows ..from the 1960's original Star-Treks to today's X-Files episodes) as people in North America and Japan, using the 60-field NTSC system are very accustomed to seeing 3/2 pulldown applied to 24fps film. Many consider it and the limited temporal judder as part of the "film" look. ..Is that right? No. ..It's still a temporal shortcoming, but people are used to it. For most North Americans, 24fps and 3/2 pulldown artifacts are considered part of the "film" look. (I've seem software that emmulates the 24fps 3/2 pulldown, for material shot in 60 field NTSC.) This also goes for 50 field PAL for Europe, where 24fps films are slightly sped up to 25fps to fit the PAL format. Is that right? Nope. But again, that's what most of Europe is used to. A, say 30fps film, would look more like video to many North Americans (not all, if we remember the true Home Theater and film buffs). And Europeans would see new artifacts not associated with Hollwood films, because the 30fps film would need to be broken down into 50 fields for the PAL video format.

Summery: More frames per second: GOOD ......
Chances of major 30 or 60fps film: SLIM ....

 

[Everlasting Gobstopper]

There's another thing to consider: if you up the frame rate to 48 or to 72, you'd lose one to one and a half stops of exposure, meaning you'd either have to light it more, or if you're outside stop down and lose depth of field, or use a faster film stock, making it more grainy. Not that the benefits of a faster shutter and higher persistence of vision wouldn't outweigh the loss of film resolution, but I guess it depends on the effect the DP would want to achieve.

 

[KyleK]

Really interesting site: http://www.maxivisioncinema.com

Don't see it ever coming to pass, though...

 

[MatthewLouwrens]

Roger Ebert has been talking about the benefits of Maxivision for years (as you can see from the column here, originally written in 1999). If the benefits are as good as claimed, then it is a shame this is not going to be adopted. And it is not. Everyone is thinking digital projection, no-one is going to change into a different type of film projection. Sadly. His explanations about why Maxivision is so much better than digital are, I feel, rather compelling.

 

[Kristoffer]

Well Maxivision sounds very interesting! I wish they would do that instead of DLP! If it is good enough for Martin Scorsese it's good enough for me!! Has any film been released in this format?

Also look at this;
Landmark Theatres and Microsoft today announced that they are equipping 177 screens in all 53 Landmark Theatres across the United States with digital cinema playback systems based on Microsoft Windows Media 9 Series, making the deployment the largest digital cinema theater circuit installation to date in the US. The newly outfitted theaters will be able to screen films encoded digitally in Windows Media 9 Series, which enables high-resolution, theater-quality experiences with up to 7.1 channel surround sound. The network rollout is expected to be completed by the end of this year. " MacNN News
Microsoft into the cinema!!

 

[Lew Crippen]

A result no doubt, of the recent purchase of ‘Landmark’ by Mark Cuban, who also owns the Dallas Mavericks and HDNET. Many of us remember that Cuban made his money on the Internet (Yahoo) and was one who got out at the right time.

No too surprising that he would strike a deal with another billionaire.

 

[Chad R]

If you're talking about film, than no, 24fps will never be replaced. It was derived at as a compromise between perception of motion and film production cost. As was pointed out, it's not just footage, but other photographic considerations. Then there's the cost of refitting theaters with projectors capapble of handling the extra load, speed of film etc.

However, what makes all of that moot is digital cinema. That's where it'll go and that's what will make 24fps obsolete. Once the conversion is done (and it may take upwards of decades to fully come) little tinkerings with quality and 'projection rate' will be much easier and cost effective to fix and upgrade.

 

[Dennis Pagoulatos]

Of course, if 24fps is replaced as a standard, it won't be a film based medium, it will certainly be digital. Probably stored at a central server, then beamed via high speed internet to each movie theaters computer equipment for display. I don't think that will take "decades" to happen though...maybe 10 years...not multiple decades though.

Film won't last because of the costs of the film itself to duplicate/ship/etc...

We should be happy that we're not being force-fed bad DLP projection which is CLEARLY not ready for primetime yet, as George Lucas would have hoped!

By the time digital really becomes a mainstream thing, NO ONE will be complaining about the quality at that point because it will easily surpass film in about 10 years as far as I can tell.

-Dennis

 

[Adam Lenhardt]

I wrote a paper on the history of Russian cinema once upon a time. I set it up with early advances in the technology of filmmaking. Edison's system used 48fps. When the Lumière brothers marketed the film medium, they reduced the frame rate by a third. The reason they did this was to save on the cost of film, as well as to reduce the clattering and grinding associated with Edison's Kinetograph as a result of having to push that much film through. The Lumière system also depended on the phenomena of intermmitent movement; Edison had strived to establish a system of continuous movement. During the silent era, various frame rates were experimented until 24 frames per second was generally accepted, half that of Edison's original design.

 

[Dennis Pagoulatos]

So, it was definitely a compromise to start with, would that be a fair assessment?

-Dennis

 

[Richard Paul]

A frame rate of 24 fps is barely adequate and has only been maintained for three reasons.

1. It is considered "acceptable" even though movies made at 24 fps wouldn't look anywhere near as realistic as movies would at 60 fps.
2. PAL is based on 24 fps and the Europeans would throw a temper tantrum if Hollywood changed to 60 fps.
3. The only way to have both 24 fps and 60 fps would be to film at 120 fps, which I don't see happening for at least 12 years.

I picked 60 fps as the ideal frame rate since it gives a great temporal resolution that is high enough for realistic motion. No one on this board who watched two versions of the same movie at both 24 fps and 60 fps would prefer the movie at 24 fps (assuming the movie was filmed at 120 fps).

 

[Alex Spindler]

I recall reading that there is a certain psychological factor that places a bias on the 24 fps rate to achieve the current 'film effect'. I wonder if the same effect is present in a 48 fps system?

 

[Adam Lenhardt]

PAL is based on 25 fps.

 

[AndyVX]

I can just see it now. Just as the film is about to start
"Sorry, You've Been Hacked... No Movie For You!" appears on screen.

 

[Paul Linfesty]

IMAX films are shot and projected at 24fps, same as 35mm and standard 70mm.

There was/is HD Imax, which shoots and projects at 48fps, but this is used for ride films such as RACING FOR ATLANTIS in Las Vegas and BACK TO THE FUTURE RIDE at Universal Studios.

 

[Jack Theakston]

When the sound systems were designed, the average run of the theaters were 11 1/8 minutes per 1000 ft. reel. This wasn't a decided thing, in fact, most of the films were being cranked at about 22 or 23, but theater owners would speed up films to get in more showtime.

Acording to SMPE in 1928:

All of these measurements were based upon what the speed was that captured the images, but projected at a rate so that projector flicker was not visable to the naked eye.

An interesting fact is that we owe the speed of 33 1/3 RPM records to the framerate of 24 FPS. This was the speed at which the synchronization of the two would be perfect upon a disc player.

A story that I once heard (and I don't know if it's true) about the first "silent" speed on the home movie projectors was that it was originally decided that 16 fps would be the norm, but that Bell and Howell found that at that rate, blistering from the lamp would still be a problem, so they upped it to 18. However, I've seen variable speed projectors, so I don't know how true this actually is.

 

[Lew Crippen]

To add to Adam’s correct comment, the Europeans project at 24 fps in their theaters, just as is done in the States.

PAL (and SECAM also) simulate 25 fps for the same reason that video in the States is based (simulates) on 30 or 60 fps. Design factors with 60 cycle current make 30/60 cycles easier from a technical perspective—just as 25 fps is quite a bit easier for TV systems where the current is 50 cps.

PAL has nothing to do with projection systems—it is a broadcast standard (just as is NTSC).