3D projection has been around for a long time in a variety of different forms. The first mainstream 3D movie appeared in the 1950s. People at that time believed that 3D was the future of the film. Movies such as "The Adventures of Africa" ​​(1952), "The Man in the Dark" (1953), "The Wax Museum" (1953), and "The Visitor of the Universe" (1953) are excited by this new technology. No. Despite the momentum, 3D did not stand firm. A small number of 3D theaters have struggled for a while because of expensive and complicated projection equipment. A small error can cause the dual projection system to lose synchronization and destroy the 3D effect. The audience was dissatisfied with the bleak image quality and less than ideal viewing conditions. The 3D movie has been crouching for many years.
3D had a brief restoration in the 1980s. This time, the technology has made some progress - the cinema can display 3D with a single projector instead of two. This greatly reduces the chances of sync errors occurring, although an incorrect bond by the projector to fix the film will still cause the film to lose synchronization. IMAX 3D also appeared during this period. In a few years, 3D enjoyed a healthy recovery, and people once again believed that 3D cinema was the right direction. However, with the introduction of "Great White Shark 3D" (1983), "Black Friday 3" (1982), and "Haunted House 3D" (1983), the audience quickly became tired of these tricks, and the enthusiasm for 3D. It also fades away.
Now, with "Polar Express", "Ghost Mother Coraline", "Monsters vs. Aliens", and of course "Avatar", the release of these movies, 3D come back again. This time, there are a few key differences that indicate that 3D may never leave the stage again. With the advent of digital cinema, synchronization and timing issues have been completely eliminated. The cost and complexity of film projection equipment has dropped, allowing 3D systems to be installed in more theaters. Filmmakers are also learning how to use 3D. The opportunistic effects of early 3D movies have been abandoned, and they now prefer a more engaging and holistic application of depth.
Perhaps most importantly, it is much easier to bring a 3D experience into the home today. With active LCD shutter glasses, a compatible display device, and a powerful enough computer, we've come to a new era: movies and video games can be viewed with high-quality 3D effects close to the commercial cinema experience. Blu-ray players will soon be able to present full 1080p movies in 3D to TVs and projectors capable of displaying 3D.
3D has a long history and has been depressed. Therefore, conclusions like “3D will not withdraw from the historical stage this time†cannot be easily made without consideration. However, with the recent technological advances in cinema and home 3D projection, this time the grasp is greater than ever before.
What is 3D?
In short, 3D technology uses two overlapping images to increase the viewer's sense of depth. One image acts on the right eye and the other image acts on the left eye. The show is shot with a dedicated camera that has two lenses that are separated from each other, much like the way your glasses see two images with a few differences. This creates a sense of depth, making the image appear to extend rearward from the surface of the screen, sometimes as if extending from the screen toward the viewer.
There are several specific implementations of competing 3D technologies, but they all aim to achieve the same goal: displaying different images for both eyes. Different techniques achieve this same goal by using different types of glasses to selectively display different parts of the picture to your left and right eyes. The difference between these methods is the way in which the two images are produced and the way in which the glasses are used to distinguish the two images.
The stereoscopic photo "stereophoto" is an imaginative vocabulary that used to describe the basic form of most practical 3D projections. The images of the left and right eyes are superimposed (usually recorded on the same film), and the difference in color is used to distinguish between the two. The viewer wears a pair of colored glasses (traditionally red and blue-green) that allow the eye to distinguish between the two images being superimposed. The end result is a sense of depth. The stereo photo mode is mainly used for the release of the home version of the movie - even if the movie does not use stereoscopic photos in the cinema - because it is cheap and easy to use. Until now, if you see a DVD or Blu-ray disc labeled "3D", it still uses a stereo photo method.
The advantages of stereo photo 3D
Easy to get. The stereo photo mode is used in today's 3D DVD and Blu-ray discs because it does not require special equipment. You don't need a "3D-ready" projector or TV. It works on your existing TV or projector, regardless of the display technology of the TV or projector, and its frame rate, aspect ratio, and resolution are all indispensable. If you can watch a movie, you can watch 3D movies as stereo photos.
cheap. 3D DVD and Blu-ray discs in stereo photo mode will not cost more than the corresponding 2D version plus 4 cheap cardboard frame glasses. Given the additional cost to consumers for 3D glasses, video display devices or DVD players, it is the cheapest 3D system on the market today.
Passive technology. We will talk about this issue more deeply, and stereoscopic 3D uses passive glasses. Passive glasses have no circuitry or electronic components, which makes them inexpensive, easy to use, and lightweight. It is ideal for children or a large audience, because eye damage or "hands-on" will not cause significant economic losses.
Disadvantages of stereoscopic 3D
color. One of the biggest problems with stereoscopic 3D and the negative impression people have on the overall 3D is the poor color. When one lens gives everything red and the other lens gives everything blue-green, the color looks a bit abnormal. Recently, post-processing has been able to adjust the color to make it look more natural, but all things still have a glowing feeling, and the color is not as solid and reliable as normal 2D.
Loss of brightness. The definition of a filter is to remove excess or something that does not meet the needs. A stereo photo 3D system works because only certain wavelengths of light reach the viewer's eyes, and all other wavelengths of light are not desirable. Therefore, the image seen through stereoscopic 3D glasses is much darker than its 2D version.
String line. Partly due to the design of the glasses, and partly due to the use of color filtering, stereoscopic 3D is more prone to "stringing" than other types of technology. The string occurs when one eye sees a portion of the image for the other eyeglass. This situation can be distracting and very obvious when it occurs, it will destroy the viewer's investment in the movie plot.
Eye fatigue. Compared to other technologies, stereoscopic 3D also tends to cause more eye strain. Part of the reason is that using red and blue-green filters changes the wavelength of light entering the eye. Cheap glasses don't have the ability to correct this. Therefore, the focal length of one eye is inconsistent with the focal length of the other, which makes the focus of the eye difficult. Coupled with the role of 3D video that has made the eyes very laborious, stereoscopic 3D can bring eye fatigue to some people - including the symptoms of headache.
Polarized light polarization systems are used in commercial theaters and other high-end applications. These methods provide a high-quality 3D experience in commercial theaters, and the popularity of digital projectors has brought 3D effects to the next level. In a polarized light system, light from one or more projections passes through a polarization filter such that all of the light waves oscillate in the same direction. Special filters on the glasses worn by the audience allow only light belonging to a certain eyeglass to pass. If you've ever seen blinds, you've already understood the concept—you can clearly see the window from a certain angle, and your line of sight will be obscured from other angles. Different polarization directions are used for both eyes so that two separate images can be projected and one image for one eye, resulting in a sense of depth.
There are currently two different polarization-based systems in the commercial 3D projection field. One version uses two projectors, each with its own polarization filter, projecting left and right eye images, respectively. This system is used for IMAX 3D playback. Another system, called RealD, uses a projector and a fast-switching single polarizer to do the same thing. The system switches very rapidly between the left eye image and the right eye image, and the polarizing filter also switches in conjunction with changes in the left and right eye images in the clockwise and counterclockwise polarization directions. Once again, polarized glasses let the viewer's eyes see only the information that belongs to each eye.
Advantages of polarized light 3D
color. The color is more accurate when using a polarized light system than a stereo photo system. Although there are some light loss from the glasses, the color is closer to its original value. Since the lens itself has almost no color, it is easier to color correct the content of the program used for the polarized light system. Especially the skin color, in a polarized light system, looks more authentic.
Passive glasses. Like stereoscopic 3D, polarized light 3D uses passive glasses, is inexpensive and does not contain electrical components. Unlike stereoscopic 3D, the frame of polarized glasses is usually made of plastic, making it more durable and reusable than paper framed 3D glasses.
String line. A polarized light 3D system has a lower string line rate than a stereo photo 3D system. Due to the nature of the polarized light, it is almost impossible for the left eye image to be seen by the right eye (the reverse is also true). If your head is too far in both directions, systems that use left and right polarized light, such as IMAX, will lose 3D, but unless you sleep on the shoulders of your neighbors, this won't be a problem.
The disadvantage of polarized light 3D
Loss of brightness. All single projector 3D systems have significant brightness reduction compared to a 2D system. For readers of ProjectorCentral who are not physicists, brightness refers to light that is reflected from a surface (in this case, the screen) at a specified angle (ie, the angle toward the viewer's glasses). This is in contrast to illuminance, which is a measure of the light per unit area of ​​a surface that is typically measured in lumens per square meter and is usually published in our projector evaluation.
In all 3D systems except stereoscopic 3D, this loss is due to the fast switching necessary to display different images for the left and right eyes. At any given moment of watching a 3D movie, one eye sees one projected image and the other eye does not see anything. In this way, each eye sees only half of the light reflected from the screen, immediately resulting in at least a 50% reduction in brightness. The reason I say "at least" is because both polarizers and 3D glasses do not have perfect light efficiency. The polarizer essentially allows only a portion of the total amount of light from the projector to reach the screen. There are some further loss of brightness in 3D glasses. The end result is that the brightness of the picture appears to be much lower than that of a 2D movie from the same projector.
This is actually one of the main advantages of using a dual projector system. Each eye benefits from the full brightness output of one projector, although the loss of brightness due to polarizers and 3D glasses still exists. The end result is a much brighter picture, all other things being the same. This last sentence is very important because it is difficult to do the same in all other respects. The most common commercial implementation of dual projector systems is IMAX, which uses a much larger screen than most RealD theaters. The projector used varies greatly over the lumen output range. The efficiency of polarizers and 3D glasses is also very different. There are too many variables in judging which system is "better", but both systems have their own advantages.
expensive. Although 3D glasses are not expensive in their own right, the rest of the system is not. At least one high-end digital projector and its special processing device are required to manage synchronization, at least one polarized light filter, and a silver-plated screen (the traditional white screen does not maintain the polarization of light). A dual projector system of course requires two projectors and two sets of polarizers.
Interference filter 3D
Another 3D implementation for commercial cinema uses a technique called interference filters, manufactured by a German company, Infitec. The system uses a projector and does not require a silver-plated screen. The Infitec 3D compatible projector has a special color wheel that is inserted between the bulb and the imaging device to separate the main color into different segments. Imagine: before, red, green, blue, now red 1, red 2, green 1, green 2, blue 1, blue 2. Special interference filter glasses allow the left eye to see only the segment labeled "1" and the right eye only see the segment labeled "2". 3D glasses use an extra filter to correct the perception of color, so what the eye sees is as close as possible to the original movie. You may have seen this technique: it is called Dolby 3D (Dolby 3D) in commercial cinema.
The Dolby 3D is not as popular for cinema projection as the polarized 3D system, but Dolby 3D is used at the world premiere of Avatar at the Empire Cinema in Leicester Square, London.
Advantages of interference filter 3D
Passive glasses. Passive glasses are a common element of 3D systems designed for commercial theaters and other large venues because of their ease of use and relatively low cost. Interference filter 3D glasses are more difficult to manufacture than polarized glasses. Therefore, they are manufactured to have high durability. The lens is made of glass, and the sturdy frame even has a lanyard hole for the anti-theft device. They are more resistant to rubbing and abrasion than fragile polarized lenses.
No silver plated screen is required. Silver-plated screens were used in all movies decades ago, but they are falling out of favor. The silver-plated screen has a larger viewing angle than the white screen, so when the projector becomes bright enough to fully illuminate a white screen, the silver-plated screen exits the stage.
The shortcomings of the silver-plated screens of the year still exist: for viewers sitting off-center, the brightness drops significantly. In a commercial theater, this includes a significant portion of the audience. Since the interference filter 3D does not require the use of polarized light, a silver-plated screen is not required, thereby improving the viewing experience of each viewer. People sitting on both sides of the theater get a more consistent screen illumination, and all viewers get the same color fidelity as non-3D movies.
Disadvantages of interference filter 3D
Loss of brightness. Any single projector 3D display will suffer significant loss of brightness compared to 2D displays on the same projector. This does not mean that the interference filter 3D and the polarized light 3D system of a single projector always have the same brightness, or that the implementation of a dual projector is always brighter than a single projector system. The single projector's polarized light system, interference filter system, and shutter glass system all have this common limitation.
Specialized equipment. It is possible to install a single projector polarizer system similar to RealD on a DLP cinema projector already in use in many commercial theaters. This modification does not require modification of the projector itself. Since the Infitec 3D mechanism works inside the projector, the theater either needs to purchase a cinema projector with the Infitec color wheel pre-installed, or a trained engineer needs to install the color wheel inside their existing DLP cinema projector.
Expensive glasses. The biggest advantage of passive glasses is that they are not expensive, so one might expect Infitec 3D glasses not too expensive. wrong. Most of the manufacturing costs of Infitec glasses are in the lens itself - the glass must be coated multiple times to distinguish between different wavelengths. Dolby's recent press conference on 3D glasses announced a wholesale price of $27.50 per pair of glasses. This is obviously a large expense for the theater, so there are many procedures to ensure that theater viewers return 3D glasses. A Dolby 3D theater I have been to ask for a photo ID to exchange for glasses.
LCD shutter glasses
LCD shutter glasses are the first high-quality 3D implementation for home use. In systems using such glasses, the video display alternately displays images of the left and right eyes at a very fast rate - up to 120 frames per second. The viewer wears an active LCD shutter eyeglass that alternately blocks the left and right eyes. Just like the effect of the DLP color wheel, this left and right alternate occurs so fast that your brain fuses the two images into one, creating a 3D sense of depth for a single image.
Advantages of shutter glasses
color. Although shutter 3D glasses are available in a variety of styles, most have lenses that do not have significant staining, which gives them the same color accuracy as polarized light. The shutter 3D glasses we have been using have a green stain, but the other brands of glasses we have seen are not stained.
String line. In terms of stringing, LCD glasses may be the best of all 3D methods because the unused eye is actively shielded by the shutter mechanism. Earlier versions had a problem with ghosting, where a portion of the previous image remained on the screen after the new image appeared. Newer, faster display technologies have completely eliminated this image error.
Relatively cheaper. The price of 3D projectors and TV sets is already very low. Today, a projector capable of displaying 3D can be obtained for only $800. Although there are other costs, such as a computer equipped with a high-end graphics card and a pair of 3D glasses for each viewer, it can still be tolerated for home applications with few viewers.
Disadvantages of shutter glasses
Active glasses. This is the main difference between LCD shutter glasses and other types of systems: the mechanism that controls which eyes see what content is embedded inside the glasses, rather than the program content or projector. LCD shutter glasses are good for a small, reliable adult audience, but it also has several weaknesses. Glasses are expensive compared to other technologies ($100 to $150 per pair of glasses at the time of publication). The glasses are complex in construction with batteries, electrical components and a fragile LCD lens. If you land on the ground, step on it, or run out of battery, it will destroy the viewer's 3D experience. And, if you have a large group of friends who want to go to your home to enjoy the 3D Super Bowl (note: NBA Annual Finals), it is too expensive to provide a pair of 3D glasses for everyone.
Synchronize. The active shutter system requires a way to synchronize the shutter action of the 3D glasses with the content displayed on the screen. Some systems use infrared emitters. The system used by Texas Instruments for projectors and televisions is called DLP Link, which uses sync pulses contained within the projected image. Although the two implementations use different sources of pulse information, the pulses themselves are identical.
The left eye pulse and the right eye pulse are different, which is why all 3D glasses that are synchronized to a particular TV set are synchronized with each other. But the projector can't know which frame belongs to that eye, which brings an interesting problem. These pulses are likely to be flipped so that one eye sees the picture belonging to the other eyeglasses. In other words, the left eye pulse and the right eye image are associated together. This is called the “pseudo-stereo effect†and this phenomenon will make you feel quite uneasy when you first experience it. The effect is a strange scene flipped inside and outside the image, as if you are viewing a sunken 3D image from the wrong side. This phenomenon often occurs, so manufacturers have corresponding countermeasures - it can be remedied by switching the display, computer graphics card or an option of the software itself. Still, it is as simple and reliable as no other type of system.
Flashing. Some people reported seeing flicker when using shutter glasses. Blinking is an effect of stopping an action that occurs when the refresh rate is insufficient. Indeed, given that each eye receives only half the refresh rate, the shutter glasses used by the projector must be very fast. For this purpose, current implementations use a refresh rate of at least 120 Hz to present an image of 60 frames per second for each eye. In the TestorCentral test, we have not encountered any flickering, so we can't comment on the prevalence or severity of this phenomenon.
Loss of brightness. The shutter glasses system uses a single projector to quickly switch between different left and right eye images, so as with other single projector systems, there is at least a 50% reduction in brightness output compared to 2D. Glasses also reduce visual brightness. Although not all glasses are the same, the models we tested have reduced visual brightness by approximately 60%, regardless of the display or the show itself. The advantage is that the glasses also reduce the black level, which significantly increases the contrast.
in conclusion
Mainly due to James Cameron's "Avatar", the commercial cinema 3D has firmly established its position. Several larger productions will soon be released in 3D theaters, including Tim Burton's Alice in Wonderland (March), Shrek 4 (May), and Toy Story 3 (June) ). These films should continue to satisfy consumers' appetite for more 3D entertainment, whether it's a commercial theater or a home theater.
Last month, at the CES show in Las Vegas, a 3D video product explosion began. This revolutionary trend of 3D video games at home and watching 3D movies seems to be as unstoppable as the fire of the original. A Blu-ray player capable of 3D playback in full 1080p movie format will be available this summer. Projectors capable of displaying lower resolutions of certain computer-derived 3D format programs are commercially available, and can be used with active LCD shutter glasses to achieve a higher quality than conventional stereoscopic 3D images. Watch the experience. 3D-enabled 1080p home theater projections will appear this fall. All of this is fascinating. 2010 will be remembered in the first year of 3D revival.
Sandwich Maker,Sandwich Toaster,Sandwich Press,Toastie Maker
Ningbo Anbo United Electric Appliance Co.,ltd , https://www.airfryerfactory.com