INTRODUCTION: Only a few years ago, seeing in 3-D meant peering through a pair of red-and-blue glasses, or trying not to go cross-eyed in front of a page of fuzzy dots. It was great at the time, but 3-D technology has moved on. Scientists know more about how our vision works than ever before, and our computers are more powerful than ever before - - most of us have sophisticated components in our computer that are dedicated to producing realistic graphics. Most computer users are familiar with 3-D games. Back in the 90s, computer enthusiasts were stunned by the game Castle Wolfenstein 3D, which took place in a maze-like castle..
Polarized 3D glasses create the illusion of three-dimensional images by restricting the light that reaches each eye, an example of stereoscopy which exploits the polarization of light. To present a stereoscopic motion picture, two images are projected superimposed onto the same screen through different polarizing filters. The viewer wears low-cost eyeglasses which contain a pair of different polarizing filters. This is used to produce a three-dimensional effect by projecting the same scene into both eyes, but depicted from slightly different perspectives. Several people can view the stereoscopic images at the same time.
HISTORY: Polarized stereoscopic pictures have been around since 1936, when Edwin H. Land first applied it to motion pictures. The so called "3-D movie craze" in the years 1952 through 1955 was almost entirely offered in theaters using polarizing projection and glasses. Only a minute amount of the total 3D films shown in the period used the anaglyph color filter method. Linear polarization was also the standard in the 80s. In the 2000s, computer animation, digital projection, and the use of sophisticated IMAX 70mm film projectors, have created an opportunity for a new wave of polarized 3D films.
WORKING PROCESS: 3D Modes There are several different methods of sending the separated views to your monitor for use with your glasses. Interlacing Interlacing is a process where the image on the screen is drawn on the alternating rows of pixels on your monitor. For instance the left image would be displayed on the 1, 3, 5, 7, ... row of pixels while your right eye is covered and then on the 2, 4, 6 , 8, ... rows while your left eye is covered Page Flipping It displays the left and right image on the screen in sync with the shutter glasses. Page flipping has higher hardware requirements than the other modes as in order to achieve a flicker free image you have to have at least 60 frames per second and with two images to display, that would mean your monitor must do 120hz refresh rate at the desired resolution your game is at.
Sync Doubling Another non-hardware intensive mode Sync Doubling which uses a sync doubler device between your monitor and video card. The video card displays the left and right images one above the other in half the vertical resolution,. Line Blanking Essentially the same as Sync Doubling, Line blanking instead of doubling the vertical lines blanks every other one which gives you the appearance of the old arcade games scan lines where there is an obvious black line interlaced in the off scan lines. Anaglyph This is probably the mode of 3D presentation you are most familiar with. These are those nerdy looking paper glasses with the red and blue lenses. Several different TV programs have been broadcast in anaglyph format such as Jaws 3D, The Drew Cary show, and I believe Third Rock also had a special 3D episode as well.
STEPS: Find a cheap pair of plastic sunglasses. Use the plastic lenses as a template to draw the correct shape onto the transparency sheet, cellophane, or acetate.
3.Cut out the lenses on the inside edge of the line you have traced on the plastic.4.Color with the red and blue markers. If you didnt use red or blue colored plastic sheeting, youll need to color each lens. Make the left lense red, the other blue.
5.Place the colored lenses back into the frames. Red goes on the LEFT, and blue goes on the RIGHT. 6.Check that they fit well. Make any adjustments needed. Then start watching your 3D movie.
TECHNOLOGY: 3D GLASSES have used polarized technology since at least 1938, when General Motors presented a 3D film at the New York Worlds fair, using viewers manufactured by Polaroid . Projection is simple, as only two filters (one in front of each of the projection lenses) are needed. Because neutral-gray linear-polarizing filters are easily manufactured, correct color rendition is possible. (Circular- polarizing filters often have a slight brownish tint, which has to be compensated for during projection.)
3D DLP TV In 2007, Texas Instruments introduced stereo 3D capable DLP solutions to its OEMs,and Samsung and Mitsubishi introduced the first 3D ready televisions. These solutions utilize the inherent speed advantage of the Digital Micro-mirror Device (DMD) to sequentially generate a high refresh rate for the left and right views required for stereoscopic imaging. 3D PDP Plasma display panels are inherently high-speed devices as well, since they use pulse-width modulation to maintain the brightness of individual pixels, making them compatible with sequential method involving shutter glasses.
LCD/LED TV Liquid crystal displays have traditionally been slow to change from one polarization state to another. Users of early 1990s laptops are familiar with the smearing and blurring that occurs when something moves too fast for the LCD to keep up. This smearing can result in a completely unviewable image when using shutter glasses. LCD technology is not usually rated by frames per second but rather the time it takes to transition from darkness to brightness and back to darkness, in milliseconds. In order to achieve an equivalent minimum refresh rate of 120 Hz, an LCD must be able to transition at a speed of not more than 8.33 ms
ADVANTAGES: Polarized glasses are generally inexpensive. Polarized glasses dont require any power. Polarized glasses dont require a transmitter to synchronize them with the display. Polarized glasses do not suffer from flicker or ghosting effects. Compared to anaglyph images, the use of polarized 3D glasses produces a full-color image that is considerably more comfortable to watch and is not subject to binocular rivalry.
DISADVANTAGES: The images for polarized glasses have to share the screen simultaneously, and therefore cannot have full resolution delivered to each eye simultaneously. A full 1080p picture results from image fusion. There are incompatible polarized systems (Circular or linear polarized.) However it produces a full color image but, it requires a significant increase in expense.
CONCLUSION: The world is a flat disc - at least for the virtual worlds of computer games, which will remain confined to 2D on the screens of their players. 3D stereo displays are (still) too expensive and (still) carry too many limitations to be of interest to the broader PC market. Autostereoscopic displays are a step in the right direction, but their high price and the need for an extra monitor for 2D use make these solutions uninteresting for anything but professional applications. Another reason preventing their acceptance in the near term is the associated reduction of image quality brought on by the halving of the horizontal resolution.
BIBILOGRAPHY: Make Your own Stereo Pictures Julius B. Kaiser The Macmillan Company 1955 page 271 Sony Digital Cinema 3D presentation Technicolor 3D "3D displays". Individual.utoronto.ca. Retrieved 2009-11-03. Manjoo Farhad. A look at Disney and Pixars 3-D movie technology. 2008.04.09. Downloaded 2009.06.07 Price list showing paper linear polarized glasses at 3 for $2, anaglyph 2 for $1 http://www.berezin.com/3d/3dglasses.htm http://www.displaymate.com/3D_TV_ShootOut_1.htm http://hdguru.com/wp-content/uploads/2011/03/Intertek-LG- FPR-Report-.jpg