RealD 3D

RealD 3D

Two pairs of RealD glasses demonstrating the polarization effect
Type	3D projection technology
Manufacturer	RealD
Website	http://www.reald.com

RealD 3D is a digital stereoscopic projection technology made and sold by RealD. It is currently the most widely used technology for watching 3D films in theaters.^[1] Worldwide, RealD 3D is installed in more than 26,500 auditoriums by approximately 1,200 exhibitors in 72 countries as of June 2015.^[2]

Technology

RealD 3D cinema technology is a polarized 3D system that uses circularly polarized light to produce stereoscopic image projection. The advantage of circular polarization over linear polarization is that viewers are able to tilt their head and look about the theater naturally without seeing double or darkened images.^[3] However, as with other systems, any significant head tilt will result in incorrect parallax and prevent the brain from correctly fusing the stereoscopic images.

The high-resolution, digital cinema grade video projector alternately projects right-eye frames and left-eye frames, switching between them 144 times per second.^[3] The projector is either a Texas Instruments Digital Light Processing device or Sony's reflective LCOS (liquid crystal on silicon). A push-pull electro-optical liquid crystal modulator called a ZScreen is placed immediately in front of the projector lens to alternately polarize each frame. It circularly polarizes the frames clockwise for the right eye and counter-clockwise for the left eye.^[4] The audience wears circularly polarized glasses that have oppositely polarized lenses that ensures each eye sees only its designated frame. In RealD Cinema, each frame is projected three times to reduce flicker, a system called triple flash. The source video is usually produced at 24 frames per second per eye (total 48 frames/s), which may result in subtle ghosting and stuttering on horizontal camera movements. A silver screen is used to maintain the light polarization upon reflection and to reduce reflection loss to counter some of the significant light loss due to polarization filter absorption. The result is a 3D pictures that seems to extend behind and in front of the screen itself.^[5]

See also

• Polarized 3D system
• Lists of 3D films
• Digital 3D
• IMAX 3D
• Disney Blu-ray 3D
• Panavision 3D
• Dolby 3D
• XpanD 3D
• MasterImage 3D
• Lenny Lipton
• 4DX

References

1. Verrier, Richard (2009-03-26). "3-D technology firm RealD has starring role at movie theaters". Los Angeles Times. Retrieved 2011-02-05.
2. ""Jurassic World" In 3D Delivers Approximately 65% Of Universal Pictures Record-Breaking International Opening Weekend". RealD. Archived from the original on June 22, 2015. Retrieved June 22, 2015.
3. Cowan, Matt. "Real D 3D Theatrical System" (PDF). European Digital Cinema Forum. Retrieved 2009-03-28.
4. "RealD - Visual Technology". RealD - Visual Technology.
5. Cowan, Matt. "Presentations (technical)". RealD Media Room downloadable files. Retrieved 2009-03-28.

Further reading

• US patent 7477206, "Enhanced ZScreen modulator techniques", issued January 13, 2009, assigned to RealD 
• US patent 6975345, "Polarizing modulator for an electronic stereoscopic display", issued December 13, 2005, assigned to StereoGraphics Corporation 
• US patent 5481321, "Stereoscopic motion picture projection system", issued January 2, 1996, assigned to Lenny Lipton 
• US patent 4884876, "Achromatic liquid crystal shutter for stereoscopic and other applications", issued December 5, 1989, assigned to Lenny Lipton 
• US patent 4792850, "Method and system employing a push-pull liquid crystal modulator", issued December 20, 1988, assigned to StereoGraphics Corporation 

External links

• Official website
• Who is Lenny Lipton? About Inventor and Chief technical officer of RealD through 2008