Real D Cinema
Encyclopedia
RealD Cinema is a digital stereoscopic
projection technology made and sold by RealD
Inc. It is currently the most widely used technology for watching 3-D film
s in theatres.
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. However, as with other systems, any significant head tilt will result in incorrect parallax
and prevent the brain from correctly fusing the stereoscopic images.
Because RealD 3D uses a single projector, it suffers a brightness disadvantage. The system causes "significant light loss"; RealD estimates the viewer sees about 35% of the light when viewing RealD 3D when compared to a similarly projected 2D image on a standard white screen.
The high-resolution, digital cinema
grade video projector
alternately projects right-eye frames and left-eye frames, switching between them 144 times per second. 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. 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 inherent losses by the polarization filters. The result is a 3D picture that seems to extend behind and in front of the screen itself.
Some viewers of 3D movies complain of headaches or nausea during or even after viewing. Those problems can be caused by the viewer tilting his or her head, making it harder for the brain to fuse the two images (due to parallax mismatch between the eyes and the cameras). It can also be caused by rapid transitions in the movie between scenes of very different depth. Directors and editors of 3D movies consequently try to avoid such transitions.
2011 in Amsterdam RAI several companies, including Sony
, Panasonic
, JVC
& others highlighted their upcoming 3D stereoscopic product portfolios for both the professional and consumer markets to use the same polarization technique as RealD 3D Cinema uses for stereoscopy. These highlighted products cover everything from recording, projecting, viewing and digital display technologies to live, recorded and pre- and post production facilities and soft- and hardware based product to facilitate 3D content creation. Their systems are interpretable, and compatible with existing, passive RealD 3D glasses.
Stereoscopy
Stereoscopy refers to a technique for creating or enhancing the illusion of depth in an image by presenting two offset images separately to the left and right eye of the viewer. Both of these 2-D offset images are then combined in the brain to give the perception of 3-D depth...
projection technology made and sold by RealD
RealD
RealD Inc. is the company that develops the RealD Cinema technology, used for projecting films in stereoscopic 3D using circularly polarized light. The company was founded in 2003 by Michael V. Lewis and Joshua Greer. Between 2005 and 2007 the company purchased StereoGraphics Inc...
Inc. It is currently the most widely used technology for watching 3-D film
3-D film
A 3-D film or S3D film is a motion picture that enhances the illusion of depth perception...
s in theatres.
Technology
RealD 3D cinema technology uses circularly polarizedCircular polarization
In electrodynamics, circular polarization of an electromagnetic wave is a polarization in which the electric field of the passing wave does not change strength but only changes direction in a rotary type manner....
light to produce stereoscopic image
Stereoscopy
Stereoscopy refers to a technique for creating or enhancing the illusion of depth in an image by presenting two offset images separately to the left and right eye of the viewer. Both of these 2-D offset images are then combined in the brain to give the perception of 3-D depth...
projection. The advantage of circular polarization over linear polarization
Linear polarization
In electrodynamics, linear polarization or plane polarization of electromagnetic radiation is a confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation...
is that viewers are able to tilt their head and look about the theater naturally without seeing double or darkened images. However, as with other systems, any significant head tilt will result in incorrect parallax
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
and prevent the brain from correctly fusing the stereoscopic images.
Because RealD 3D uses a single projector, it suffers a brightness disadvantage. The system causes "significant light loss"; RealD estimates the viewer sees about 35% of the light when viewing RealD 3D when compared to a similarly projected 2D image on a standard white screen.
The high-resolution, digital cinema
Digital cinema
Digital cinema refers to the use of digital technology to distribute and project motion pictures. A movie can be distributed via hard drives, optical disks or satellite and projected using a digital projector instead of a conventional film projector...
grade video projector
Video projector
A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...
alternately projects right-eye frames and left-eye frames, switching between them 144 times per second. The projector is either a Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
' Digital Light Processing device or Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
's reflective LCOS (Liquid crystal on silicon
Liquid crystal on silicon
Liquid crystal on silicon is a "micro-projection" or "micro-display" technology typically applied in projection televisions. It is a reflective technology similar to DLP projectors; however, it uses liquid crystals instead of individual mirrors. By way of comparison, LCD projectors use...
). A push-pull electro-optical
Electro-optics
Electro-optics is a branch of technology involving components, devices and systems which operate by modification of the optical properties of a material by an electric field...
liquid crystal
Liquid crystal
Liquid crystals are a state of matter that have properties between those of a conventional liquid and those of a solid crystal. For instance, an LC may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of LC phases, which can be...
modulator called a ZScreen
ZScreen
ZScreen is a push-pull electro-optical liquid crystal modulator that is placed immediately in front of the projector lens or computer screen to alternately polarize the light from each video frame...
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. 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
Motion blur
Motion blur is the apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie or animation. It results when the image being recorded changes during the recording of a single frame, either due to rapid movement or long exposure.- Photography :When a camera...
and stuttering on horizontal camera movements. A silver screen
Silver screen
A silver screen, also known as a silver lenticular screen, is a type of projection screen that was popular in the early years of the motion picture industry and passed into popular usage as a metonym for the cinema industry...
is used to maintain the light polarization upon reflection and to reduce reflection loss to counter some of the inherent losses by the polarization filters. The result is a 3D picture that seems to extend behind and in front of the screen itself.
Viewing comfort
3D systems for movies using polarized light cause a loss of screen brightness due to the inherent filter absorption. The polarization filter in front of the projector blocks half of the projected light, and then split again one half for each eye, resulting in only 25% of the projected light reaching the eye. This is compensated somewhat by the silver screen which boosts the brightness to about 35% of the original. The overall effect is that of wearing a pair of slightly darkened glasses in a standard movie theater, which could be compensated for by using brighter projector lamps.Some viewers of 3D movies complain of headaches or nausea during or even after viewing. Those problems can be caused by the viewer tilting his or her head, making it harder for the brain to fuse the two images (due to parallax mismatch between the eyes and the cameras). It can also be caused by rapid transitions in the movie between scenes of very different depth. Directors and editors of 3D movies consequently try to avoid such transitions.
Other systems that use circular polarization
At IBCInternational Broadcasting Convention
The International Broadcasting Convention, more commonly known by its acronym IBC, is an annual trade show for broadcasters, content creators/providers, equipment manufacturers, professional and technical associations, and other participants in the Broadcasting industry...
2011 in Amsterdam RAI several companies, including Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
, Panasonic
Panasonic
Panasonic is an international brand name for Japanese electric products manufacturer Panasonic Corporation, which was formerly known as Matsushita Electric Industrial Co., Ltd...
, JVC
JVC
, usually referred to as JVC, is a Japanese international consumer and professional electronics corporation based in Yokohama, Japan which was founded in 1927...
& others highlighted their upcoming 3D stereoscopic product portfolios for both the professional and consumer markets to use the same polarization technique as RealD 3D Cinema uses for stereoscopy. These highlighted products cover everything from recording, projecting, viewing and digital display technologies to live, recorded and pre- and post production facilities and soft- and hardware based product to facilitate 3D content creation. Their systems are interpretable, and compatible with existing, passive RealD 3D glasses.
See also
- List of 3-D films
- Digital 3DDigital 3DDigital 3D is a non-specific 3D standard in which films, television shows, and video games are presented and shot in digital 3D technology or later processed in digital post-production to add a 3D effect....
- IMAXIMAXIMAX is a motion picture film format and a set of proprietary cinema projection standards created by the Canadian company IMAX Corporation. IMAX has the capacity to record and display images of far greater size and resolution than conventional film systems...
- Disney Digital 3-DDisney Digital 3-DDisney Digital 3-D is a brand used by the Walt Disney Company to describe three-dimensional films made and released by the Walt Disney Studios Motion Pictures and shown exclusively using digital projection....
- Dolby 3DDolby 3DDolby 3D is a marketing name for a system from Dolby Laboratories, Inc. to show three-dimensional motion pictures in a digital cinema.- Technology :...
- XpanD 3DXpanD 3DXPAND 3D is a brand name of a system for presenting three-dimensional films in a digital cinema, home theater, video games and other applications. XPAND utilizes active-shutter 3D glasses...
- MasterImage 3DMasterImage 3DMasterImage 3D is a company that develops stereoscopic 3D systems for theaters and auto-stereoscopic 3D displays for mobile devices.-Technology:...
- Lenny LiptonLenny LiptonLeonard "Lenny" Lipton is a well known author, filmmaker and stereoscopic vision system inventor.Lipton wrote the lyrics to the song Puff the Magic Dragon as a 19-year-old at Cornell University. He graduated from Cornell University where he majored in physics. The song was a hit in 1963 for Peter...
External links
- RealD website
- RealD Cinema page
- RealD Theater Locator
- Dolby Digital 3D vs Real D / Master image systems Video Technology Blog
- Who is Lenny Lipton? About Inventor and Chief technical officer of RealD through 2008