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Digital Movie Projection: Can It Live Up To The Hype?
hobb writes "OK, so Roger Ebert's not a technical genius, but he's written an interesting piece on the future of digital movie projection (theatres, not home.) Read his essay here. Digital for home systems is great, but will 1280x1024 be good enough for theatres? That's about 10mm dot pitch, folks...
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Film's resolution is considerably higher than HDTV's. This post is just plain false.
The system used for the recent Phantom Menace digital projections was the Texas Instruments DLP system. The specs are here:
r wars.shtml
http://www.ti.com/dlp/products/cinema/specs_sta
Or here for more on the system:
http://www.ti.com/dlp/products/cinema/
Yes it only has a resolution of 1280 by 1024. HD systems at home do have more resolution than this, but the home HD systems are cathode rays not projection. It's much harder to make a projection system very high resolution than a tube system.
But the resolution will get even higher. Hughes has a system already the ILA-12K (http://www.hjt.com/products/ila12k.html) that does 2000 by 1280. It will keep increasing.
The effective resolution of film (ie. the analog messy strip of celluoid) is around 4000 by 3000 pixels. Digital special effects that are mixed with live film footage are rendered at aywhere from 2048x1550 to the above 4K rsolution.
But the advantage of digital is that the colour reproduction is much more accurate and when you project film, the film is moving at high speed and jitters from side to side so you get blurring.
I imagine only films that have a large proportion of their content created digitally will go with digital projection in the near future. Then there is a real advantage for the director that he knows the colours he sees on the computer screens when they are creating the effects are exactly what will be projected. When you shoot to film there are a huge array of isssues with film stock, look up tables, gamma curves and the only way to know what your colours will actually look like is do go out to film and do a test screening (expensive).
Digital projection is the future but the current systems will improve a lot before it becomes the only system used.
What I know of this comes from still photography, but its also at 35mm (i.e. a negative 24x36mm), so I can say something intelligent.
If you do the sums for a 35mm still, it is considered "sharp" if a single point on the object maps to a cirlce of diameter less than 0.004 inches on the negative (known as the "circle of confusion"). That corresponds to a digital resolution of around 3000x2000. Of course you can go finer. But that is roughly the best performance you can expect from a 35mm film.
Now, whether this makes any difference depends on whether you can see such a small object. The question is: given two small dots in the scene, can you see whether there is one dot or two in the projected image? The point at which the two dots merge into one is the resolution, and the angle subtended by the two dots is the angular resolution. I'll dodge the difference between angle for the camera and angle for the viewer: projection systems are designed so that the middle seats get the right perspective.
The angular resolution of a good human eye is 1/60th of a degree (1 arc minute). So an ideal cinema screen would need to match that with around 60 pixels per degree. Right now I'm wearing spectacles, and without moving my head they put a frame on my vision about 80 degrees wide. I haven't measured a cinema screen from the centre seat, but I'd expect something nearer 40 degrees. 40 degrees times 60 pixels per degree gives 2400 pixels. Which is not too far off what 35mm film gives (at its theoretical best).
So current XVGA systems are not up to the job of replacing film, but give us a 3000x2000 pixel screen and it will look better. And Moore's Law suggests that we will be able to do that fairly soon.
Of course there are other issues. As others have noted you have the problems of physical wear and dirt getting onto film, and the costs of printing, versus the 100% reproducability of digital and the costs of piping all that data around. But you can bet that the studios have looked at these numbers and figured that the lifecycle costs look interesting. And no doubt someone has told them of Moore's Law too.
I remember the same argument in the early days of digital audio. The first CD players sounded harsh in the high treble thanks to the steep filters required. Analogue purists declared that digital would never replace analogue. But where is analogue now? A niche split between rich die-hards and poor elderly people who can't afford to replace their existing LPs. Physical analogue film will go the same way.
Paul.
You are lost in a twisty maze of little standards, all different.
As much as I respect Roger Ebert, I have to say that he's just missing the point completely here.
Ebert contends that film-based systems will be better than digital in the future because film will provide a better-quality image than digital can; and on this count, I think he's absolutely right. Even uncompressed DV lacks the "warmth" (for lack of a better term) of film, and the MaxiVision system he touts sounds like it provides an image that nobody in the DV world can hope to match.
The problem is, image quality is unimportant. Now, before everyone gets up in arms here, think for a second. Who is clamoring for image quality that is better than today's films? General audiences? Nope, they are happy with the cruddy image from a poorly set up projector in a shoebox theater in their shopping mall. Theater owners? Nope, they make more money by dividing their space into multiple small, low-tech screens rather than lovingly setting up one beautiful screen and cutting the number of movies they can show by 11/12ths. Studios? Nope, they know that what makes them money: formulaic movies with name stars presented on as many screens as possible. If they could make money presenting more striking images, they'd all be doing IMAX films by now.
So where it counts -- money -- MaxiVision & other advanced film systems are irrelevant, because nobody wants them bad enough to pay for them. Digital, however, is a different story. Digital offers a big money benefit to one of these players -- the studios -- because it cuts dramatically one of the biggest cost in distributing a film: prints & advertising.
P&A is one of the biggest line items on a film's budget, running into millions of dollars. Each theater which is going to show your film needs a "print" (an analog dupe of the film) to run through their projector. In fact, they need more than one, because prints wear out or get scratched or otherwise start to die after awhile. When you consider that each print is absurdly expensive, and that a movie that "opens wide" goes to 2,500+ theaters, you can see how this gets expensive quick.
Digital changes all this. Suddenly you can stop sending reels of film around (which are expensive) and start sending around magnetic disks (which aren't). Even better, you could conceivably ship the image via a fiber optic cable or satellite connection and avoid "prints" altogether. Then "P&A" just becomes "A" and you've just saved millions, which to a Hollywood executive means that his project is that much more likely to be profitable and thus advance his career.
So, while I understand Ebert's position and wish that we lived in a world where he was right, where the quality of the experience was the prime factor, we don't, and he's wrong. Digital will overtake film, not because it's better, but because it's cheaper -- and even the most beautiful MaxiVision 48 images won't convince the Hollywood moneymen to ignore that math.
-- Jason A. Lefkowitz
Read my blog.
Duplicating a film print is an extremely expensive and time-consuming process, and for that matter, you can only make so many copies before destroying the original. So instead of making a copy for every theater, studios make a limited number of copies, and force the theaters to take turns. (Usually by staggering international premieres.)
Digital "film" would solve this problem, by allowing unlimited lossless duplication.
MSK