Sony's largest camera

. . . As you can see, there are only digital versions and movie versions.

-2K digital version (quality index: 2K)

Let's talk about the FULL HD that everyone is becoming more and more familiar with. Now everyone is familiar with the saying of full HD and 1080p when buying TV or video camera, that is, the picture resolution reaches 1920X 1080, and the standard Blu-ray disc BD program also supports this resolution. Accordingly, the maximum resolution of DVD format is only 720X480, which is less than half that of Blu-ray.

At present, the mainstream of digital movies you see in cinemas is 2K, 2048× 1556 resolution (there are also some low-end projectors in China with 1.3K resolution, 1280× 1080 resolution). In fact, it's a little higher than BD, so watching BD with PS3 at home is not much different from that in cinemas.

-35mm film version (1K-2K)

The traditional film version is more complicated. Originally, the resolution of film is generally not nominal, so it must be calculated that the resolution of high-quality 35mm film is about 4K or slightly better than 4K; In addition, according to the different production level, the resolution of post-production masters is also different, 4K is good and 3K is poor. However, we are fortunate to see that the possibility of a master film is infinitely close to zero! Because the cinema shows copies that have been "copied" n times. If the copy quality is good, the resolution will probably be a little more than 2K, and the poor resolution will even be lower than 1K, and it will decay with the increase of screening times. If you copy and show more times, it will scratch and there will be black rain on the screen; After many times of high temperature baking, the film will fade and the film base will warp, resulting in out of focus. It seems that the picture quality of the movie version will not exceed the mainstream digital version of 2 K. The advantage of movies lies in the strong shock brought by huge pictures and the unique texture, color style and depth of field effect of films, and there will also be preferences.

As can be seen from the above analysis. There are four main determinants of the quality of the movies we see in the cinema. The first two are photographic carriers: a. photographic equipment, b. production specifications; The latter two are projection carriers: C. copy instructions D. projection equipment.

-4K Digital Edition (4K)

At present, 70% of commercial feature films still use 35mm film movie cameras. As mentioned above, this film material can be used to make a master tape with a resolution of 4096x3 1 12. Here is a concept of DI digital intermediate film. It is a digital cinema system (2K or 4K) based on the filming production process. It uses a film scanner to scan the film into a high-resolution digital image, uses a digital post-production process to make a complete digital master film, and finally converts the film back to film or ultra-high-definition resolution. At present, most of Sony's films adopt 4K specifications for post-production.

Although the projection equipment of most chain cinemas is still a standard 2K-DLP system, the digital optical processing (DLP) technology developed by Texas Instruments is adopted. However, Sony also launched the only commercialized 4K projection equipment in the world, occupying a few high-end markets, and released digital 4K versions of movies such as Spider-Man 3. At present, the newly opened Jinyi Cinema Central Store in Shanghai has purchased a 4K digital projector, and HKEx Yonghua also has one.

More and more movies use digital photography, such as Lucas Star Wars Episodes 2 and 3, Superman's Return and so on. But at present, the digital movie cameras used in these blockbusters actually have a resolution of only 1920X 1080, which is just equivalent to the projection level of 2K. Therefore, at present, movies shot with digital movie cameras cannot produce digital 4K versions.

-IMAX Movie Edition (6K)

Having said that, I will talk about the concept of IMAX. IMAX (Image Maximum) is a film projection system, which can project films with larger and higher resolution than traditional negatives. The standard IMAX screen is 22 meters wide and 16 meters high, but it can be played on a larger screen. At present, there is only one commercial IMAX hall in Shanghai, and the Science and Technology Museum only shows science and education documentaries, while there are three in Beijing, but only china national film museum is the real film version. In order to greatly increase the resolution of the image, IMAX uses a special 70mm film, while the real IMAX film is shot with a 70mm film camera.

The theoretical resolution of IMAX camera is 18K (per frame 18000X 13433 pixels), but the film studio can't handle such a large picture, and accordingly they reduce the resolution to less than half of the original resolution, only 8K, which is the maximum resolution of film scanning. Therefore, at present, the production limit of the master film in the film industry is 8K, and the resolution can reach 6K when the IMAX theater shows 70mm films, which is the limit of commercial screening.

Although IMAX is an excellent film format from a technical point of view, it has not been popularized. The cost and transportation difficulties of IMAX production and broadcasting make it shorter than ordinary movies (generally 40 minutes, and 90-minute IMAX movies have appeared in recent years), and the themes are mostly documentaries suitable for the institutions such as science and technology museums. At present, there are only two commercial films produced and shown in Imax format, the Dark Knight has more than 30 minutes, and the Transformed king kong 2 has four scenes (about 1 minute, but the non-IMAX film version does not have these scenes). The former was not shown in China, and the latter I saw in china national film museum, the crystal version of the huge image, put into those four IMAX scenes, the image suddenly became 27mX2 1m, full screen, shocking your aphasia. It's really pleasant.

-IMAX DMR version (4K-6K)

In order to promote its film system, IMAX introduced a DMR technology to distribute more commercial films. The process is as follows: First, the production company gives the 35mm film copy of the film to IMAX, which uses DMR technology to scan each frame of 35mm film at the highest resolution and convert it into digital pictures; Then, each picture is optimized by using proprietary image enhancement technology and finally printed on 70mm film. Most IMAX feature films released this year, such as Harry Potter: Half-Blood Prince and Transformed king kong 2 (most scenes in this film), are IMAX DMR. I think its picture quality is higher than 4K and lower than 6K.

-IMAX Digital Edition (2K-4K)

However, the cost of making copies of IMAX movies has inhibited its development. The company also vigorously promotes the so-called IMAX digital cinema system. The principle of this system is: IMAX uses DMR technology to process the film copy sent by the production company, making it "Digital Film Packaging" (DCP). The resolution of this format can reach 4K, and then it can be saved on hard disk and sent to the cinema for screening, so the cost of copying is very low. The main components of IMAX digital projection system that cinemas need to configure include: two digital projectors with 2K resolution, which adopt digital optical processing (DLP) technology developed by Texas Instruments; A broadcast server specially made by Doremi Labs; And IMAX's own image enhancement equipment. The pictures projected by the two projectors are superimposed, so the actual resolution of a movie picture is still 2K, but the new IMAX projection system can enhance the fidelity of the image, and the picture quality is better than that when using one projector. For example, Beijing Shijingshan Wanda claims to be the first digital IMAX cinema in Asia, but in fact, the picture quality is discounted, only higher than 2K and lower than 4 K. IMAX should spare no effort to promote this sub-optimal thing for economic benefits. This year's Star Trek only released the digital IMAX version.

There are many cottage practices in China. In order not to let the IMAX hall with few film sources idle, Beijing UME Huaxing set up a digital giant screen. In fact, it is to throw ordinary digital 2K material on the IMAX giant screen. If the quality is not up to standard, the definition will be terrible. This is a bit suspicious of deceiving consumers.

Now speaking of 3D movies, with the popularity of the first live-action 3D digital movie "Journey to the Center of the Earth" in 2008, more and more 3D movies have entered people's sight. Of course, there are natural advantages in making 3G animated films. Since 2009, almost all animation giants will release 3D versions. This time, "Avatar" pushed the live-action 3D movie to an unprecedented height, so it was a revolution in the film history.

At present, the international 3D projection systems are mainly divided into five categories, and domestic cinemas are also in use.

* XPAND system

Digital 3D can be divided into active technology and passive technology. The so-called active mode is to use the high-speed switching of the left and right lenses of glasses to achieve the 3D effect, mainly using the XPAND system nuvision 3D technology. Active system installation is very convenient. The cinema only needs a signal controller to control when all the glasses in the cinema are switched. But the disadvantage is that the cost of glasses is very high, and a pair usually costs one or two hundred yuan. If you go to see a 3D movie, you will find that the glasses are well-made and have the XPAND logo, which is the signal receiving system. There are many cinemas in China. For example, Shanghai Jinyi Central Store has adopted this technology.

* RealD system

Nowadays, passive systems are widely used in cinemas, and glasses with passive systems are very cheap. RealD is this category, and its share in the North American market is over 80%. However, due to the special metal screen, it is different from the usual 2D white screen, and only Keda of Shanghai Luomei has adopted this technology in China.

* Dolby system

Considering the inconvenience of using active glasses and metal curtain, the design concept and realization advantages of Dolby 3D technology are passive glasses and white screen. So most cinemas in China use this system.

All the above 3D technologies have fatal shortcomings at this stage, that is, the brightness is too low. When using active or passive 3D, the luminous efficiency is only 65,438+00% (Reald is 65,438+05%), which is converted into brightness of 65,438+0/4 to 65,438+0/5 of 2D. Therefore, if the life of the original light bulb in the cinema is similar, it will feel very dark when watching 3D. This is also the reason why watching 3D movies in China is too dark to affect the impression. Kodak's RealD is relatively the most praised.

* dual camera 3D or single camera dual lens 3D

The only solution now is to display the contents of the left eye and the right eye with dual cameras 3D, which can greatly improve the brightness. However, due to the cost problem, domestic cinemas are rarely used. Now Legendary Times Studios has a set of Barco dual-camera 3D projection system. In addition, the Golden Harvest Studio, which is about to open in Suzhou, has also installed a set. The 3D effect of these two cinemas will be much better than that of a single cinema. In addition, I have seen the 3D of the Film Museum, and the brightness is fine, but I haven't got their official explanation as to whether their system is dual-machine 3D, but there is no doubt that there is no problem in choosing this place.

Based on its 4K digital projector, Sony introduced a 3D solution with single camera and dual lens. Because the 4K ultra-high-definition chip can easily accommodate two 2K pictures, and a single machine can output two 2K pictures at the same time, the 3D projection is smooth and smooth, and there is no high-frequency flicker and blurred pictures, thus eliminating the visual fatigue and dizziness caused by the time difference of the 3-frequency single-machine 3D projection system. It is a stand-alone 3D projection system with the best image quality at present. I guess the effect is still a little worse than that of dual-computer 3D. Shanghai Jinyi Central Studios doesn't know whether it will apply its 4K Sony projector to 3D movie playback (please note that if you don't use 4K Sony, it will have no advantage over the digital 3D halls of other cinemas. Even if it is used to display 2D numbers, it is far from being able to output 4K content because the copy is only 2K. My impression is that Sony projectors are mainly equipped with RealD technology.

*IMAX 3D

IMAX3D is the projection technology of IMAX stereoscopic movies. IMAX3D uses two IMAX-specific 70mm films, one for each eye, and provides two independent images through polarized filter glasses (passive) or infrared synchronization system (active) combined with electronic glasses. Combined with IMAX giant screen, IMAX3D can produce realistic full-field stereoscopic effect. IMAX 3D technology not only uses the world's largest IMAX film, but also uses double films to record and play the images of the left eye and the right eye respectively, making the images more stereoscopic and clear, and the colors more vivid.

However, there are very few films actually made with IMAX 3D, and they are all documentaries, such as Deep Sea. Of course, most of the time, movies are produced by digital 3D technology and transformed by DMR technology. There are two systems when playing: film and digital. The membrane system should be better, because it has the potential of 6KX2, and the number is still 2KX2. In addition, because IMAX plays the movie version and the digital version of 3D, it is a dual-machine system, so the overall performance is definitely better than that of ordinary digital 3D on a single machine. Fans in Taiwan Province Province also confirmed that the digital IMAX 3D version is better than the Bisogni 4K RealD version.

However, Avatar mainly displays 3D effects, and its image quality and resolution are not first-class. About 8 Sony HDC-F950 digital cinema cameras and 8 CineAlta F23 digital cinema cameras were used in the whole movie. Among them, 8 sets of dual-camera 3D shooting systems have been developed. This 3D photography system is named: Fusion Camera -3D System. Although both of them are top-notch, they are both at the resolution level of 1920X 1080. This explains why James Cameron said in an interview that the IMAX version will not be much better than the ordinary digital 3D. It's not that IMAX technology is not good, but that he didn't use this technology to shoot. IMAX digital 3D and dual-camera 3D both output two 2K images, which should meet the photographic specifications. Of course, whether the later computer production and DMR transformation will obviously improve the quality of IMAX movie version, or make IMAX digital 3D obviously superior to dual-computer 3D version remains to be confirmed.

To sum up, the order of choosing to watch Avatar is:

IMAX Movie Edition (Shanghai Peace Movie Capital, Beijing is China National Film Museum) > IMAX Digital Edition (Beijing Shijingshan Wanda) > Dual-machine 3D Digital Edition (Beijing Legend Age or Film Museum) > Sony 4K 3D Digital Edition (Shanghai Jinyi Central may be) > RealD Single-machine 3D Digital Edition (Kodak, Shanghai Miracle City) > Other Single-machine 3D Digital Edition > 2D Digital 2K Edition > 2D Movie Edition.