Je vous signale la publication d'une entrevue avec James Cameron dans Variety, où il donne sa vision des technologies de projection dans les salles de cinema pour les années à venir.
http://www.variety.com/VR1117983864.html
Publication: Variety
Auteur: David S. Cohen
date : 10 avril 2008
S'il développe surtout son point de vue sur les conséquences artistiques et économiques du cinéma stéréoscopique (en "3D") qu'il utilise pour son prochain film "Avatar", il y a un passage que je trouve très intéressant pour le home cinema:
Question : I'm hearing that there are already calls to increase the frame rate to at least 30 fps for digital 3-D because certain camera moves, especially pans, look jumpy in 3-D. I saw that in the Imax 3-D "Beowulf." You've been an advocate for both 3-D and higher frame rates. Have you seen the problem and do you have any thoughts on it?
Réponse: 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.
Question : Other than that, for digital 3-D, would you rather see energy going into moving from 2K to 4K, or into moving from 24 fps to 48 or 72 fps, and why?
Réponse : 4K is a concept born in fear. When the studios were looking at converting to digital cinemas, they were afraid of change, and searched for reasons not to do it. One reason they hit upon was that if people were buying HD monitors for the home, with 1080x1920 resolution, and that was virtually the same as the 2K standard being proposed, then why would people go to the cinema? Which ignores the fact that the social situation is entirely different, and that the cinema screen is 100 times larger in area. So they somehow hit on 4K, which people should remember is not twice the amount of picture data, it is four times the data. Meaning servers need to be four times the capacity, as does the delivery pipe to the theater, etc.
But 4K doesn't solve the curse of 24 frames per second. In fact it tends to stand in the way of the solutions to that more fundamental problem. The NBA execs made a bold decision to do the All Star Game 3-D simulcast at 60 frames per second, because they didn't like the judder. The effect of the high-frame-rate 3-D was visually astonishing, a huge crowdpleaser.
I would vastly prefer to see 2K/48 frames per second as a new display standard, than 4K/24 frames per second. This would mean shooting movies at 48 fps, which the digital cameras can easily accommodate. Film cameras can run that fast, but stock costs would go up. However, that could be offset by shooting 3-perf, or even 2-perf, because you'd get the resolution back through the higher display rate. The 48 fps negative or digital master can be skip-printed to generate a 24 fps 35mm DI negative for making release prints, so 48 is the magic number because it remains compatible with the film-based platform which will still be with us for some time, especially internationally. 30 and 60 fps are out for that reason. Anyway the benefit of 30 is not great enough to be worth the effort, especially when 48 is so easy to achieve. SMPTE tests done about 15 years ago showed that above 48 frames the returns diminish dramatically, and 60 fps is overkill. So 48 is the magic number.
Of course, the ideal format is 3-D/2K/48 fps projection. I'd love to have done "Avatar" at 48 frames. But I have to fight these battles one at a time. I'm just happy people are waking up to 3-D.
Maybe on "Avatar 2."
Pour James Cameron, c'est visiblement dans la fréquence, plutôt que dans la définition qu'il faut chercher une amélioration des qualités de projection. Du coup, est-ce que pour le home cinema, cela ne conduit-il pas à favoriser le choix de projecteurs capables d'afficher 48, voir 72 images par seconde, même si c'est pour répeter 2 à 3 fois la même image ?
Pour l'instant, je crois que les seuls films tournés véritablement en 48 fps (48 images différentes) sont certains films au format IMAX. En avez-vous vu? Avez-vous noté une différence?
Cordialement,
Supercastor.
