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Disney Digital 3-D is a brand used by the The Walt Disney Company to describe digitally animated three-dimensional films shown exclusively using digital projection. It is essentially a Disney brand of Real D Cinema technology. Disney Digital 3-D is not related to Real D, it is exclusively a production method. Real D, Expand, Master Image and Dolby 3D are all exhibition technologies used to play back 3D movies.

Disney re-released The Nightmare Before Christmas, three times, in a remastered 3-D version, first on October 20, 2006, and second on October 19, 2007; it was re-released again on October 24, 2008. Disney also released a 3-D version of its computer-animated feature Meet the Robinsons. Then Disney launched Hannah Montana & Miley Cyrus: Best of Both Worlds Concert on February 1, 2008 and on February 27, 2009 Jonas Brothers: The 3D Concert Experience, both concert movies in Disney Digital 3-D. The first Disney Digital 3-D movie ever to be made by Pixar is Up. Pixar's other films Toy Story and Toy Story 2 are set for re-releases in Disney Digital 3-D as a double feature on October 2, 2009 and Toy Story 3 to be released June 18, 2010. Tron Legacy will also be in this format sometime in 2010.

How it works

Audiences viewing a film presented by Real D are given a pair of plastic 3D glasses. The glasses have circularly polarized lenses, each polarized differently. Circular polarization allows much greater head movement than linear polarization without loss of 3D effect or ghost images. This increases audience comfort and helps to mitigate the "3D headache" caused by many 3D systems, especially those relying on film projection.

The movie is projected digitally, with a single Christie, Barco or NEC DLP Cinema projector (other digital projection technologies would work as well if fitted with the proper equipment) at 144 frames per second, six times as fast as a normal movie. Every 1/24 of a second (the projection frame rate for normal 2D movies on film) the two scene views called "right eye" and "left eye" are each shown 3 times (6 flashes of image on the screen matching the 6 times higher projection rate). Due to persistence of vision, the 72 image frames and 72 black frames fed to each eye in a given second should be perceived as a relatively flicker-free image. Due to the low original framerate, the channel separation isn't optimal during horizontal camera movements which results in minor ghosting effects.

In front of the projector lens sits the Z-Screen, an electronic device developed by Lenny Lipton from Stereographics. It inserts a polarizing screen that matches the polarization of either the right lens or left lens of the glasses worn by the audience. When the left-eye-matching Z-Screen is in place, the viewer's right eye sees nothing at all (or almost nothing) while the left eye sees a normal looking frame. For the next frame of the movie, the Z-Screen swaps the polarizing screen to match the right eye lens in the glasses worn by the audience. Now the audience sees nothing (or nearly nothing) with the left eye and a normal but slightly shifted version of the frame in the right eye. The brain knits together the alternating left-right perspectives into a seamless 3D view of the movie scene.

The single projector setup has a number of advantages over previous 3D systems:

• It eliminates most "ghost images" caused by the left eye seeing a bit of the right-eye frames and vice versa.
• It eliminates any form of temporal (time) or spatial misalignment of the left-eye and right-eye frames that plagued previous 3D projection systems relying on movie film. The mechanical jitter of the film in the projector and the poor frame-to-frame matchup generated most of the dull headache 3D side effect caused by the eye muscle strain — along with the much improved, but still slightly flawed, horizontal/vertical polarization system seen for the last 20 years or so in motion simulation amusement rides, IMAX 3D and in limited other venues (Walt Disney World, Disneyland etc.).

The main trouble with polarized 3D systems for movies is a loss of screen brightness. The polarizing screen in front of the projector blocks half of the outgoing light, causing an equivalent loss of brightness on the screen. However, in this system, a silver screen is used , which reflects the projected light without changing its circular polarization so that the light from each image is able to pass through the viewer's left or right lens with no further loss of brightness. However, half of all other ambient and reflected (i.e. non-polarized) light in the theater is blocked by the polarizing lenses of the viewer's glasses. Therefore, the viewer perceives an overall dimming by 50%, but no loss of contrast between the screen and its surroundings. The overall effect is that of wearing a pair of slightly darkened glasses in a standard movie theater. The fact that only one eye is seeing an image at any given moment has no bearing on the perceived brightness of the movie, as the human brain does not process brightness by adding the contribution from each eye. This fact becomes evident if one performs the simple experiment of closing one eye and noting that the brightness of one's surroundings has not changed. In physical terms, brightness is based on light intensity, which is measured in units of power per unit area, and is thus unaffected by the size or number of sensors, assuming they are all equidistant from the light source.

Confusion

Disney Digital 3D is not a presentation format. Disney Digital 3D is a production process. It is not a version of Real D, and is completely independant of Real D. Disney 3D movies can be presented using the Expand, Real D, Master Image or Dolby 3D system and the studio is officially agnostic to which one is used. This article is very misleading.

Titles

References

1. http://www.prnewswire.co.uk/cgi/news/release?id=149089

External links

• "Disney Hatches Chicken Little in Digital 3D" (AWN, October 31, 2005

• Disney technology
• 3D imaging
• 3-D films