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The 3d120-frame film, for example, is Ang Lee's "Billy Lynn's Halftime Battle."
Common resolution diagrams
4k is an image resolution concept, according to the international common DCI cinema standard, 4K resolution refers to the pixels of each frame of the film is 4096x2160. The so-called 4K projection actually contains two aspects, one is that the resolution of the film source is 4k, and the other is that the resolution of the projector is also 4k, and only such a projection can be called 4k projection.
In addition, the clarity of the picture actually felt by the audience is also related to the screen size and viewing distance, which is simply the pixel density actually felt by the human eye. There is a concept called "retina screen", that is, when the density of pixels received by the human eye is greater than the resolution of the human eye, the human eye cannot perceive pixel particles.
Corresponding to the theater screening link, because the picture from the projector to the screen will be enlarged, so the pixel density will become smaller, if you look close to the screen, you can still see a pixel point, so the audience must be outside a specific distance, in order to feel the clear presentation of the 4K image.
Strictly speaking, the current 3D movie can only be called "stereoscopic movie", the real 3D should refer to the three-dimensional space xyz in three directions have position information, such as holograms, and the projection of stereoscopic movies is still carried out on a flat screen, but only through the separation of the left and right eye pictures to make the human eye three-dimensional, but for the sake of brevity, the following still refers to "3D" to refer to "stereoscopic".
Speaking of which, it is necessary to explain the principle of stereoscopic vision. The reason why humans can feel the spatial stereo is because the two eyes have a spacing (an average of 65mm), so that the angle at which the two eyes observe things will be different, and the images obtained will also be different, which is called parallax.
It is precisely because of the existence of parallax that the human eye will produce a three-dimensional sense, because objects at different distances, their parallax is not the same, so parallax can correspond to the depth, which is the principle of stereoscopic film - to provide two pictures with parallax on the left and right, and through stereoscopic glasses and other technologies to separate the picture during the screening, respectively into the audience's left and right eyes, so that the audience can feel the depth of different objects in the picture.
Avatar 3D footage
3D movies have been popular for a while as early as the 1950s, but because the production and projection technology at that time was still very backward, and the picture quality was also very poor, it would be extremely uncomfortable to watch. The real solution to the 3D movie viewing experience is "Avatar", the camera-pace stereoscopic shooting system developed in the production of this film is still the most advanced shooting system in the world, which can provide accurate and comfortable pictures, and most of the current "live-action 3D" movies are used in this system.
"Avatar" has promoted the boom of the stereoscopic film market, but due to the cost and technical limitations of actual shooting, "conversion 3D" has become the choice of more films, after five or six years of improvement, now the stereoscopic transformation technology is no longer criticized, but there is still a gap with the effect of actual shooting.
The human eye receives information as a continuous process, but technically speaking, "continuous" is just an idealized concept: time is continuous, but technology cannot divide time infinitely, so there must be a smallest unit, in the field of film, this unit is the "frame". The number of frames per second refers to the segmentation accuracy of continuous time that technology can achieve.
The larger the number of frames, the smaller the motion blur
Therefore, the filming process of the film is to record the changes in light changes over a continuous period of time into discrete static film pictures. In the screening stage, in order to make these static pictures "move" again, it is necessary to apply the principle of visual retention of the human eye. After the photoreceptor cells of the human eye receive light and generate nerve potentials, this potential does not disappear immediately, but gradually decays, and this attenuation process is visual persistence. Experiments have shown that the visual persistence time of the human eye is about 0.1 seconds, so as long as the speed of screen switching is greater than 12 frames per second, the human eye will connect the previous frame of the persistence image with the next frame of the picture to form a continuous visual feeling.
The reason why the current film takes 24 frames / second as the frame rate standard is determined by a variety of factors, a large factor is that the mechanical equipment at that time can achieve a limited speed of operation, and the higher the frame rate, the greater the consumption of film, so the frame rate of 24 frames / sec was finally selected. This standard has been in place for nearly a century, during which time high frame rate formats have emerged, but they have not been widely promoted due to the high cost. It wasn't until the 48-frame release of "The Hobbit" that the commercial operation of the high-frame rate system became possible.
It should be pointed out that high frame rate movies include shooting high frame rate and projection high frame rate two aspects, shooting high frame rate has been achieved very early, but for so many years the projection has been adhering to the standard of 24 frames, people often say "slow shot" refers to high frame rate shooting, normal frame rate projection, only when the shooting and projection speed is the same, and are much higher than 24 frames / second, can be called high frame rate film. And 120 frames, as the name suggests, is shooting and screening to reach 120 frames per second.
On this question, Ang Lee gave a detailed answer in the interview. Although once again at the forefront of technology, Ang Lee has never been considered to be a technical control by fans, on the contrary, his works will always infect the audience with profound and delicate character portrayal and spiritual thinking.
However, as a person who dares to challenge himself and is not afraid of failure, Ang Lee is always willing to achieve his narrative purpose in an extraordinary way. When preparing for the filming of "The Fantasy Drift of Young Pi", Ang Lee clearly knew that the key to the success of the film lies in multiple story lines, and there are many possibilities hidden under the surface plot, which can trigger the audience to think about the secrets behind the story.
The 3D effect of this scene in "The Fantasy Drifting of The Young Pi" is very strong, and the front and back scenes are clearly layered
How to use pictures to show this depth of thinking? There is no better way than 3D. That's why we see a lot of stacked shots in Pi's Fantasy Drift, layers of different depths used to represent different content, thus presenting multiple threads of the story, both subjective and objective.
Soon Ang Lee found that after using 3D technology, the existing 2K resolution was not enough to support the increased amount of information in the picture, you know, even "Avatar", the camera resolution used in the shooting was only 1920x1080, which could not fully present the true wonders of the 3D world. Therefore, 4K resolution has great benefits for 3D movies, the audience can see more details, and the producer can also incorporate more information into the picture.
3D and 4K weren't Ang Lee's firsts, but when it comes to 120 frames of high frame rate technology, Ang Lee was the first to be brave enough to try it out. According to Ang Lee, 120 frames are meant to truly present the complex inner activity of human beings. We all have this experience, that is, in a short period of time, we have thought about many things and experienced extremely rich and complex inner activities.
"Billy Lynn" uses 3D/4k/120 frames to reflect the character's rich heart
The technique used in past movies to show this inner activity is "slow motion", which stretches out and spreads out what happens in a short period of time, thus adding information to this moment. But Ang Lee believes that this is different from the real human experience, time should not be stretched, but the density of information per unit of time can be increased, which is the purpose of using 120 frames, which can bring more information to the audience in a second. This change may be subtle, but the human eye often inadvertently captures details that are not usually noticed.
The story structure of "Billy Lynn's Halftime Battle" is to depict the inner activities of the actor Billy Lynn when he is invited to participate in the National Football League halftime show. Based on the above reasons, Ang Lee boldly adopted the top collocation of 4k, 3D, and 120 frames for shooting and screening, so as to maximize the detailed expression changes of the male protagonist and set off the psychological activities of the characters in different environmental backgrounds.
Ang Lee once admitted that the biggest technical challenge of "Billy Lynn's Halftime Battle" is that there is no reference standard, everything has to be tried, even if the technology pioneer Douglas Trumpbu has experimented with this specification of shooting and screening a few years ago, but it is only a product of the laboratory environment.
Ang Lee couldn't even tell what kind of effect he wanted to achieve, but he knew he was exploring a whole new way of watching movies, even audiovisual language templates. He believes that there will be new format specifications for movies in the future, and audiences will gradually accept this new movie-watching experience, and the concept of what we call "cinematic sense" may change radically in the future.
As for the changes that 4k/3d/120 frame technology has brought to "Billy Lynn's Halftime War", it can be roughly discussed from three aspects: production, screening and movie viewing experience.
The high resolution of 4K is very demanding for acting, and the performance of the male protagonist's sister (Kristen Stewart) is universally praised
First of all, in the shooting and production stage, the increase in resolution makes the flaws in the picture more easily detected by the audience, so the entire set, costume props, makeup, and actor performances must be improved, and it is difficult to adopt some opportunistic methods as in the past.
In order to reduce the sense of vertigo caused by the change of parallax, 3D film pays attention to the smoother movement of the mirror, the editing rhythm is more soothing, and the scene scheduling should be strictly controlled, and the composition design of the picture should also be based on the favorable 3D presentation.
The most significant change brought about by the high frame rate is the surge in data volume, which adds a lot of difficulty to both data management and post-production. In addition, the time synchronization of all equipment on the shooting site must be adjusted to 120 frames per second as the standard, especially the flicker frequency of the luminaire must be synchronized with the camera, so as not to make the picture flicker and dim.
There are only 5 theaters in the world that can play 3D/4k/120 frames, and the picture shows one of them: Beijing Bona U-Tang Store
From the perspective of projection technology, the only one that can achieve the 4k/3d/120 frame projection standard is the double-ended rgb three-color laser projector produced by Christie, which replaces the traditional xenon light source with a three-color laser light source, which not only has higher brightness and contrast, but also significantly improves the color reproduction, tolerance, color gamut range, etc., thus ensuring the ultra-fine picture quality required for this high-specification projection. The cost of this projection technology is very high, and the equipment has not been mass-produced, so there are currently only 5 cinema halls in the world equipped with this projection equipment.
From the perspective of the audience, 4k and 3D are not new, only the high frame rate has never been experienced by Chinese audiences (the "Hobbit" trilogy has not introduced a high frame rate version in China), so the after-effects are mainly concentrated on the technical point of 120 frames. Most viewers believe that when they first come into contact with a 120-frame/sec movie, they will have the illusion of watching an Ultra HDTV.
In the war scenes, the disappearance of this movement blur makes the sense of scene stronger, but at the same time, the "sense of cinema" is also weakened, more like watching high-definition television
Because after the frame rate is high, the same motion is divided into more and finer moments, and the amount of motion in each moment becomes smaller, so the motion blur in the picture will also be reduced. The audience has long been familiar with the 24 frames / second motion blur, and when suddenly looking at an image with almost no motion blur, they will feel that the picture is abnormally real, and even lose the so-called "film texture" and become a high-definition live broadcast, which is also the reason why the audience generally reflects that it is easy to play.
The increase in frame rate leads to a wider aperture, a smaller depth of field, and a strong contrast between the front and back of the virtual, is this contradictory to the pursuit of realism?
In addition, the increase in frame rate leads to a shorter exposure time, so in order to ensure the amount of exposure required for the picture, the lens aperture will be opened wider than before, which will also cause the depth of field in the picture to become smaller. It stands to reason that large depths of field are more conducive to 3D images, and in Billy Lynn's Halftime Battle, it often happens that except for the main body of the picture is clear, all other background elements are blurred, especially in some close-ups and close-ups. This strong contrast between the former and the false is not the feeling of the human eye to see things in reality, so it seems to contradict the pursuit of the real feelings of the human eye.
Article source: http://news.mtime.com/2016/11/15/1563061-all.html#p2