Is 24fps becoming outdated?

[Cesar Rubio]

No, the blur would exist for the entire distance that the object moved. Consider a simple example:

 

Suppose we have a locked off shot of a blue sky, and a ball is thrown thru the shot from one side to the other. Suppose the ball moves three times its diameter in 1/300 second. We shoot this with one camera at 300 fps, 360 degree shutter, and another at 25 fps, 180 degree shutter. Each frame we get from camera #1 has a blur on it that is one ball diameter high by four ball diameters long (the distance it moves, plus its own length). The beginning of the ball blur in any frame is exactly where the end of the ball blur was in the previous frame. Every point along the center of the the ball blur is made by exposure from the ball for 1/3 of the time, and exposure from the sky for 2/3 of the time.

 

Now suppose we take six consecutive frames from camera #1, and combine them by adding up all the pixel values and dividing by six. The result is a blur on the path of the ball that is one diameter high by 19 ball diameters long. The ball moves 6 x 3 = 18 times its diameter over the six frames from the high speed camera. Every point on the trajectory of the center gets ball exposure for 1/18 of the time, and sky exposure for 17/18 of the time. Compare that with the matching shot from camera #2, which exposed one frame during the same amount of time that camera #1 exposed six frames. The blur would be identical, provided that we have the same speed of edge passage on both, as could be the case with CCD's. Even if camera #2 had a significantly slower shutter edge passage, the difference wouldn't be all that great. It's mostly the averaging of frames from the fast camera that makes the blur in its downconverted material match the slow camera.

 

Well, OK, so maybe it's not such a simple example.... ;-) But if you really want complicated, imagine it with a shutter under 360 on the fast camera, and figure out how you reconstruct the ball blur for the five gaps between frames. That's undersampling.

 

-- J.S.

 

 

 

Hi John:

 

For outside work (in a sunny day) this might work, but using 1/300th for interior work is most of the time not possible with current HD sensors.

 

I prefer 30 fps over 24 fps for 3-D stereo work.

 

60 fps indeed look very much like "soup operas" , but is a necessity with sports....BTW 60p loos better than 60i.

 

Unfortunately, Hollywood dictates the "standards" for 2-D and 3-D movies, at this time 24 and 48 are the norm. (DCI)

 

If we shoot let's say at 1080/24 fps, then a 720/60 fps conversion is easier (just like 24p to 60i) and also it almost carries the same bandwidth for TV broadcasting and a possible future Blu-ray distribution.

 

That way you cover "your bases" of a possible cinema (2-D or 3-D) and a "home viewing" distribution.

 

 

Thanks,

 

Cesar Rubio.

Cambridge Wisconsin, USA.

http://www.davidrubio3d.com/

[John Sprung]

However most people cannot really tell the difference between 720p and 1080p .....

 

It's not the people, it's the displays they watch. On even the best HD CRT's, there isn't a difference to be seen. But on a big screen with a DLP projector, the difference is dead obvious to pretty much everybody. When the old 720p Varicam first came out, we did A/B tests against the old F-900 and screened them at Modern. That's why we approved the Varicam for off-speed work only.

 

 

 

 

 

 

-- J.S.

[John Sprung]

Wait a minute, Karl, I have a camera with a shutter opening of 345.6 degrees which means 96 percent light and 4 percent dark. Video is not closer to 360 degrees. Check under AONDA

 

NTSC TV spends 92% of its time scanning fields, and 8% doing vertical retrace, with the screen blank. With ATSC, fields and frames get stored in buffers and can be displayed however the TV set maker chooses.

 

 

 

 

 

-- J.S.

[John Sprung]

For outside work (in a sunny day) this might work, but using 1/300th for interior work is most of the time not possible with current HD sensors.

 

Yes, this is a BBC research presentation, not something they plan to put into widespread use any time soon.

 

 

 

 

 

 

-- J.S.

[Joshua Jackson]

My sophomoric response to the original post:

Personally, I'm not interested in an approx. 25% budget increase on film stock to shoot at 30fps as opposed to 24fps.

I have a gut feeling not many studios are going to be all that interested in that kind of increase either.

So, no. I highly doubt 24fps will become outdated anytime soon.

I think Karl's right...that pretty much just leaves a film vs. digital debate.

[Cesar Rubio]

It's not the people, it's the displays they watch. On even the best HD CRT's, there isn't a difference to be seen. But on a big screen with a DLP projector, the difference is dead obvious to pretty much everybody. When the old 720p Varicam first came out, we did A/B tests against the old F-900 and screened them at Modern. That's why we approved the Varicam for off-speed work only.

 

-- J.S.

 

John:

 

In your experience, don't you think that 720/60p DLP projection might work for a 14 feet (4 Mts) wide screen for 3-D stereo?

 

I am planing to see if Hollywood will approve a DCI 720/60p "addendum" for Small Venue 3-D cinemas in poor countries...or small cities in prosper ones:

 

 

http://www.davidrubio3d.com/view_topic.php...amp;forum_id=88

 

 

The theater project I am planning would have only 56 seats...7 seats by 8 rows.

 

 

Thanks,

Cesar Rubio.

[John Sprung]

In your experience, don't you think that 720/60p DLP projection might work for a 14 feet (4 Mts) wide screen for 3-D stereo?

 

It's a matter of taste, price/performance point, and timing. I know that for 2D, 720 isn't as good as 1080. But almost as good for a lot less money could well be a price/performance point that would sell.

 

The wild card is timing. How long before the price of 1080p drops to or below what 720p costs now? If you invest in the 720 setup, you have to make your money back and a profit before the competition gets 1080.

 

As for a formal DCI addendum, you probably don't need it. You're the customer, so you can order a 720p/60 downconversion. The way to approach it would be to talk to theater owners in your target market, and see where they get their product. Then ask those distributors.

 

 

 

-- J.S.

[Chris Keth]

Back on topic, Steven Jolly of the BBC has done some work on higher frame rates, which he presented at HPA this February. His conclusion is that the best choice is 300 fps, but with a 360 degree shutter.

 

So I take it film as an acquisition format isn't even considered by the BBC anymore? <_<

[Cesar Rubio]

It's a matter of taste, price/performance point, and timing. I know that for 2D, 720 isn't as good as 1080. But almost as good for a lot less money could well be a price/performance point that would sell.

 

The wild card is timing. How long before the price of 1080p drops to or below what 720p costs now? If you invest in the 720 setup, you have to make your money back and a profit before the competition gets 1080.

 

As for a formal DCI addendum, you probably don't need it. You're the customer, so you can order a 720p/60 downconversion. The way to approach it would be to talk to theater owners in your target market, and see where they get their product. Then ask those distributors.

 

-- J.S.

 

 

 

Thanks for your input John.

 

But since the DCI requires "especial" (read expensive) servers and 2K projectors combination in order to "decode" the "key" to project BIG Studio movies in digital cinemas, it wont be as easy as you mention....

 

I am planning to use self made workstation as "digital cinema server", and this kind of 720p projector that with 5000+ lumens will be enough for a 4 mts screens. (two for a 3-D set-up)

 

 

http://www.bhphotovideo.com/c/product/5183...XGA_1280_x.html

 

 

http://dr-3dcameraco.com/product_info.php?...cdac2c1a1188828

 

 

Now we need to figure out a method that would work with such simplified projection setup...that is "anti-piracy" which is what Hollywood cares more about (I would too).

 

 

Thanks,

 

Cesar Rubio.

Cambridge Wisconsin, USA.

http://www.davidrubio3d.com/

[Chris Keth]

There is a 100th anniversary Lumiere collection in which they used Hand cranked cameras and traditional techniques for little shorts directed by a variety of film makers including Lynch. I forget what its precise name was.

 

Lumiere and Company.

[Thomas James]

What I was refering to was that as far as flat panel LCD televisions are concerned motion blurring is the biggest complaint rather than a television lacking enough fine detail. Therefore the Blu-Ray 720p format which can go up to 60 frames per second would offer the sharpest picture for action movies. Also the Blu-Ray 1080p format displayed at 30 frames per second would also significantly reduce motion blurring. As far as digital cinema goes this of course would be 2K which can go up to 60 frames per second.

[Thom Stitt]

Took the liberty of copying some of James Cameron's thoughts on this topic:

 

James Cameron:

For three-fourths of a century of 2-D cinema, we have grown accustomed to the strobing effect produced by the 24 frame per second display rate. When we see the same thing in 3-D, it stands out more, not because it is intrinsically worse, but because all other things have gotten better. Suddenly the image looks so real it's like you're standing there in the room with the characters, but when the camera pans, there is this strange motion artifact. It's like you never saw it before, when in fact it's been hiding in plain sight the whole time. Some people call it judder, others strobing. I call it annoying. It's also easily fixed, because the stereo renaissance is enabled by digital cinema, and digital cinema supplies the answer to the strobing problem.

 

The DLP chip in our current generation of digital projectors can currently run up to 144 frames per second, and they are still being improved. The maximum data rate currently supports stereo at 24 frames per second or 2-D at 48 frames per second. So right now, today, we could be shooting 2-D movies at 48 frames and running them at that speed. This alone would make 2-D movies look astonishingly clear and sharp, at very little extra cost, with equipment that's already installed or being installed.

 

Increasing the data-handling capacity of the projectors and servers is not a big deal, if there is demand. I've run tests on 48 frame per second stereo and it is stunning. The cameras can do it, the projectors can (with a small modification) do it. So why aren't we doing it, as an industry?

 

Because people have been asking the wrong question for years. They have been so focused on resolution, and counting pixels and lines, that they have forgotten about frame rate. Perceived resolution = pixels x replacement rate. A 2K image at 48 frames per second looks as sharp as a 4K image at 24 frames per second ... with one fundamental difference: the 4K/24 image will judder miserably during a panning shot, and the 2K/48 won't. Higher pixel counts only preserve motion artifacts like strobing with greater fidelity. They don't solve them at all.

 

If every single digital theater was perceived by the audience as being equivalent to Imax or Showscan in image quality, which is readily achievable with off-the-shelf technology now, running at higher frame rates, then isn't that the same kind of marketing hook as 3-D itself? Something you can't get at home. An aspect of the film that you can't pirate.

 

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Let's assume right now that this debate reasonably should be confined to digital filmmaking and projecting. It's been mentioned here several times that it makes very little sense to update the film standard with new framerates.

 

I like that Cameron's getting at a theater-specific experience. If we eliminate what TVs can do at home, now or in the near future, if we concentrate only on what high end digital cinema projectors are capable of... What could/should we be seeing at the movies? And has anyone here seen a digital projection at high resolution and high framerate? Cameron seems to be absolutely sold on across-the-board faster framerates in digital cinemas. I haven't seen it myself. I don't know if many people have. The big debate these days with digital always seems to be resolution. The closest I've seen is an HD monitor on set displaying an overcranked slowmo image. To my eye, it was off-putting. Hyper video. At the very least, it would take some getting used to.

 

But on a giant theatrical screen? I'm interested in the question of pure cinema experience - We're SO accustomed to 24fps when we go to the movies. It seems reasonable to me that a faster framerate at high resolution could result in a more "truthful" image.