3d cinema technology · 2017-08-23 · 3d cinema technology bernard mendiburu* vp innovation...

3D Cinema Technology

Bernard Mendiburu*VP Innovation Volfoni, Los Angeles, CA, USA

Abstract

This chapter describes the technologies and trade-offs related to the projection of stereoscopic 3D imagesin a cinematic environment. Particular emphasis is placed on the struggles throughout the industry toidentify an optimal technology related to 3D glasses. Some discussion is considered about next-generation solutions, but autostereoscopic 3D is not expected in the cinema environment for more thana decade.

List of Abbreviations

AS Active stereoscopyECB Electronically controlled birefringenceLCoS Liquid crystal on siliconLCS Liquid crystal shutterPS Passive stereoscopy

Introduction to 3D Cinema Exhibition

Current 3D projection technology used in commercial movie theaters uses a dual-channel work flow,displaying two discrete images to the audience, one for the left eye and one for the right eye. In computergraphics animation movies, such as Toy Story 3, the two video streams are produced with two virtualcameras set in a 3D synthetic world. In real-world productions, such as Avatar, pairs of cameras are linkedtogether in a specialized apparatus referred to as a “3D rig” or “camera rig,” and the left and right imagestreams are produced, mixed, transported, and broadcasted in parallel and synchronicity.

The word “stereoscopic” literally means “seeing volume,” but it is often mistakenly understood tomean “dual imaging system.” This is probably because of the association we have with the notion of“stereoscopic sound,” another dual-channel stimuli system we are familiar with.

This chapter will not cover multichannel 3D (technologies based on integral imaging, depth acquisi-tion, or synoptic cameras and that can be seen without 3D glasses on autostereoscopic displays). Becauseof the display resolution and viewpoint synthesis requirements, the mass production of autostereoscopicdisplays and content for this next generation of 3D visualization is still 10–15 years away, beyond theaccuracy limit of technology forecasting (see also chapters “▶Autostereoscopic Displays,”▶Head- andEye-Tracking Solutions for Autostereoscopic and Holographic 3DDisplays,” and “▶Emerging Autoster-eoscopic Displays”).

3D projection systems are limited by virtue of the fact that a single screen must be able to show both leftand right images. Therefore, the left and right channels must be multiplexed in order to share a single

*Email: [email protected]

*Email: [email protected]

Handbook of Visual Display TechnologyDOI 10.1007/978-3-642-35947-7_112-2# Springer-Verlag Berlin Heidelberg 2015

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http://link.springer.com/SpringerLink:ChapterTarget





reflecting surface and then filtered out before reaching the eyeballs of the audience. So far, no betterapparatus has been designed to that end than glasses, and so today, all cinematic solutions employ sometype of glasses-based technology. (Note that in some autostereoscopic 3D cinema prototypes, the left andright images are beamed to the supposed position of the left and right eyes of the audience, but thisapproach requires a rather rigidly defined theater design and has not gained popularity. As such, in current3D theaters, the multiplexing is in time, polarization, wavelength, or a combination. It can be done usingsingle or dual projectors, before or after the imaging device, inside or outside of the projector.

The combination of all encoding and decoding stages involved in 3D cinema reduces the lightefficiency to less than 20 %. This is currently the biggest challenge facing 3D cinema, because luminanceis a key quality factor. The other major challenge facing the industry is related to cross talk between thetwo channels.

This chapter is structured on presenting the emission, encoding, transmission, and then decoding andreception of the 3D visual message.

• Emission refers to the stereoscopic projection setup and method.• Encoding is based on a combination of various multiplexing processes.• Transmission relies on light bouncing on the theater screen.• Decoding is done by various eyewear technologies.• Reception is assumed by the audience’s eyes and brains in a process called stereopsis that is described

elsewhere (see chapter “▶Human Factors of 3D Displays”).

Projection Setup and Mode

Projection Setup3D projection can be achieved using a single-, dual-, or multiple-projector setup. Simpler setups have theadvantage of easy deployment and operation; more complex setups offer better image quality, resolution,light level, contrast, and discrimination, each increasing with the number of involved projectors.

Single-Projector SystemThe single-projector setup is preferred for small theaters. It is a fail-proof concept and only marginallymore complex to operate than a regular 2D digital projection system. The single-projector 3D solution hasbeen used for many decades. The advent of digital cinema has enabled the widespread implementation of3D theaters, particularly thanks to the imaging speed of DLP

®

chips. Other single-projector systems,based on reflective liquid crystal, or simply 35 mm film were introduced more recently and rely onperiscope lenses that realign left and right images. All single-projector systems suffer from lowluminance – as one might expect from filtered light from a single bulb.

Dual-Projector SystemsA dual-projector system is more powerful than a single-projector system, with twice the amount of light tobegin with and the stability of full-time illumination when running passive stereo. Despite its apparentsimplicity, with each projector displaying one of the two image streams, two projector solutions strugglewith issues related to setup and operational complexity. Dual projection setups require more specializedequipment and staff to preserve left-right coherent image geometry and sharpness. Aging light bulbs willneed to be re-calibrated to maintain equal light levels and match color accuracy between the twoprojectors. Keystone correction is needed to compensate for the trapezoidal image warping due todifferent projection paths. To that effect some projectors use a camera that analyzes the picture to detect


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and correct asymmetries. Such constraints relegate dual projection systems to be used primarily in high-end theaters and special venues.

Almost all dual projection systems use passive stereo and polarization multiplexing. There have beenattempts to use dual active projection, with two DLP projectors working in synchronicity, to increase lightlevels on large screens. But such a solution did not prove very effective in field use. If the two images arenot perfectly aligned on screen, the images are blurry. There are some rare cases of dual active projectionusing SXRD 4 K projectors with mechanical shutters to generate high-resolution images on regular whitescreens. Such setups are used in scientific visualization and have not been used in commercial cinemasince 1920 due to their complexity and expense.

Multiple Projector SystemsSpecial venues are common users of gigantic screens and 3D imagery. “King Kong 3D 360” recentlyopened at Universal Studios in Los Angeles. Sixteen projectors are used to project the movie. Suchsystems use the same principles as scientific visualization systems use to align and match images, such asedge matching, genlock, and frame lock. Such systems are one of a kind and not very common.

Active and Passive StereoscopyThe distinction between active stereoscopy (AS) and passive stereoscopy (PS) is an important one tounderstand when considering 3D display technologies. Because it is a central concept that interacts withmany other components (such as the number of projectors and the active or passive glasses), the generalpublic, as well as a good share of industry professionals, tend tomisunderstand it and inappropriately label3D systems as “active” or “passive.” But to be clear, single-projector setups can run in active and passivemodes, just as passive glasses can be used to watch passive or active stereo. The AS and PS attributionsonly distinguish between concurrent or alternative transmission of the left and right image streams.

Passive Stereoscopy with Pixel CollocationIn passive stereoscopy, left and right images are displayed full time. This is most likely achieved using twoprojectors. Another approach is to share the imaging surface of a single projector and realign the pictureson screen using a periscope optical mount with prisms placed between the projector and the two lenses.Through this method, 4 K digital projectors can also be used as passive stereo single 2 K projectors.This has been done in the 1950s using standard film. Modern reiterations of this process were introducedin 2009 and 2010 (by Technicolor, Oculus, and Panavision).

Active Stereoscopy with Time MultiplexingIn active stereoscopy, left and right images are alternatively displayed, fast enough for humans not tonotice that each eye is seeing a black screen half of the time. If the refresh rate is close enough to retinalpersistence, the brain only detects inconsistent light levels referred to as flickering. Over 100 Hz theflickering effect is considered as unnoticeable at the required light levels in the theater.

In current AS digital 3D projectors, the stereoscopic multiplexing is run at 144 Hz, with each leftand right frame alternatively displayed three times following a [L R L R L R] pattern repeated 24 times asecond.

The main problem with AS is that depth artifacts are introduced by the interaction between fasthorizontal movement and the average time delay between left and right image streams. An objecttraveling across the screen in 1 s at the current AS projection rate of 144 fps will be integrated by ourvisual system with a parallax artifact of 0.69 % of image width. As a reference point, most depthplacements in modern 3D movies stay within a parallax of 1–2 % of image width. Luckily for AS intheaters, film makers avoid fast camera movement, in order to avoid strobe effects, or rely on motion blur


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to mask it. Still, motion-depth artifacts of up to 0.1% of the screen can occur and be noticeable, conflictingwith other depth cues like occlusions.

Projection Technologies

The current resurgence of 3D cinema relies heavily on the so-called glass-to-glass digitization withimages being stored and processed exclusively as discreet numerical values from the camera lens to theprojector’s optical system. Even though 3D has been strongly associated with the deployment of digitalprojectors in theaters, classic film distribution made an unexpected comeback as a projection method for3D movies in 2009.

3D cinema imaging systems are based on high-end 2D projectors used in specific ways, with additionalapparatus used to align and multiplex the left and right images. In this section, we cover all projectionsystems, including the latest digital cinema products and film-based retrofit technologies. Themultiplexing uses a combination of time, light polarization, and wavelength technologies that will bepresented in the next section.

Digital 3D ProjectionDigital projectors are key assets in the current 3D cinema resurgence because they allow for pixel-accurateimage projection and AS retrofit at marginal incremental costs. Texas Instruments’ DLP technology wasthe only digital system on the 3D market for a while, although it is now competing with Sony’s SXRDtechnology.

Digital Micromirror Device or DLP®

ProjectionDLP

®

is the commercial name of the DMD, a technology that uses an array of micromirrors to createimages (see chapter “▶DLP

®

Projection Technology”). Being built upon a full on/off light controlsystem, it modulates gray levels by pulse-width modulation. Data range of 10 bits (1024 light levels) isdithered by flashing 1024 times 1-bit images. Color is generated by using three imaging channels, fed withmonochromatic red, green, and blue lights.

In this configuration, dividing the imaging time into two discrete images may look like a simple datasource and microcode upgrade issue. Actually it involves a huge bandwidth load on data processing chipsthat control the DLP chip. Driving a 2 K chip, with two megapixels, at 10 bits of depth color, involves2 Gb of data per frame. In 3D, with the projector running at 144 fps, the process generates 288 Gbpsof data.

Therefore, in 2005 the first generation of “digital 3D” cinema projectors were run at lower resolutionsto accommodate for the increased requirements of the stereoscopic triple flash.

Recent developments of DLP technology include the deployment of a dual DLP projector systemknown as “digital IMAX” and the release of the first generation of projectors based on new 4 K DLPchips.

Liquid Crystal on Silicon, LCoSThe other family of digital imaging processors used in professional cinema are based on liquid crystals(see chapter “▶Liquid Crystal on Silicon Reflective Microdisplays”) and are marketed under the SiliconX-tal Reflective Display (SXRD) brand by Sony. Until recently, it was the only 4 K projection system, butwas too slow to sustain active stereoscopy from a single projector. A periscope lens was developed and isnow available as “RealD XL-S.” It separately deals with upper and lower parts of the light beam comingfrom the lens, polarizes, and aligns them on the screen. The resolution, theoretically full 2 K, is actually


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852 � 2048, due to the actual frame format in theater releases and the necessity of a buffer area betweenthe two images.

Film-Based 3D ProjectionThere may be thousands of digital 3D projectors in the USA, and tens of thousands are on their way. Filmprojectors still count in the hundreds of thousands in the USA and a few millions in the world. As such,many industry leaders are betting on innovative 3D-on-flim distribution technologies to take advantage ofthe installed base of film-based projectors.

Single-Strip 3D Film ProjectionIn 2010, Technicolor presented a film-based 3D projection system using an above/below image format onthe 35 mm support and periscope lens attachment that polarizes and realigns pictures on the screen(reference to be supplied).With such systems, however, in the event of a film rupture, projectionists fix thesupport by slicing out one frame. Unfortunately, this inverts the left/right alternation of images andsubsequently presents “inverted stereo” to the audience. Addressing this headache-triggering hazard, 3Dinventor Lenny Lipton introduced a few months later another system where the images are recorded sideby side on the film strip and adequately rotated and realigned by a patented 3D lens attachment (Lipton2011; Lipton et al. 2011).

These two solutions are aimed at helping retrofit tens of thousands existing 35 mm projectors in theUSA for a fraction of the cost of a complete digital replacement and should help spread the 3D renaissanceto worldwide locations where the economy cannot support the expense of a digital 3D projection system.

It should be noted that film-based solutions like these generate potential depth placement or verticalparallax, and scratch and dust on the film generate retinal rivalry (Figs. 1 and 2).

Dual-Strip 3DDespite popular belief, the 1950s 3D movies were not shown using low-end red and blue color encodingsystems. The Golden Age 3D movies were shown in full color, using two projectors and Polaroidpolarizing filters. The main issues were the synchronization of the two projectors and the need for anintermission. Regular 2D movie reels could be loaded alternatively on two projectors, and they wouldswitch over, sometimes automatically. When a 3D film was shown, both projectors were running at onceand an intermission was required to reload them.

All these issues were addressed in the design of the IMAX 3D projection system, with electronicsynchronization, complex gate registration device using a vacuum pump, and giant platters to hold longruns of 70 mm film.

104

105

Prior Art

103LEFT

a b

RIGHT

106

102

101

4032

42

1014

12 302628

16

3836

3444

Fig. 1 (a) Left and right images on a single-strip film, classic over/under, and (b) lens attachment (Reprinted from Liptonet al. 2011)


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Multiplexing Techniques

Time MultiplexingTimemultiplexing is the simplest and cheapest multiplexing used in the stereoscopic display industry. Theprocess was discussed in Section 2.2.2 of this chapter.

Time multiplexing requires an imaging engine fast enough to completely switch from left to rightimages with no residual effect. In the case of the DLP chip, full transition is immediate. Still, some darktime has to be included to match the other apparatus involved in the encoding or decoding of the 3D, andthat dark time concept applies to many stereo projection systems.

Active polarizer solutions, like the RealD’s “Z-Screen” or active liquid crystal shutter glasses, havelonger transition times than DLP technology and require the imaging device to project a dark frame whilethey get to their appropriate left or right state. Dolby 3D and MasterImage systems use encoding wheels.The border between the left and right half-circle filters must have crossed the whole light path before animage can be displayed.

304

301

302

303

305 306

901

902

LE

FT

RIG

HT

LE

FT

a

b

RIG

HT

903

909

908

911

913

910

912

904

00

00

00

00

00

00

905

907 906

Fig. 2 (a) Left and right images on a single-strip film, new side-by-side method, and (b) lens attachment (Reprinted fromLipton et al. 2011)


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Wide-Band Wavelength MultiplexingAnaglyphic encoding is the most common form of 3D imaging, noticeable because of the red-cyan glasseswidely used as a visual synonym for “3D,” even in recent advertisements for current full-color digital 3Dproducts. The basic principle of anaglyph technologies is to assign two of the red, green, and bluechannels to one eye and the remaining one to the other. That color affectation will define the efficiency,comfort, color, and luminance behavior of the overall system. The most used is red/cyan (green + blue).Two other color combinations are currently used: blue/yellow (red + green) suffers from a huge lumi-nance asymmetry and has to be tweaked to blue/orange or blue/brown (Sorensen et al. 2004; Starks).Green/magenta (red + blue) offers the most balanced luminance and resolution in 4:2:2 YUV videocodecs used in almost all digital delivery systems (Cugnini 2009; Lanfranchi and Brossier 2010).

The current development of full-3D display systems in theaters and at home is paradoxically revivingthe interest in such color-based 3D encoding, for they allow film companies to repurpose 3D content sothat the vast majority of the global audience can enjoy 3D without upgrading their display systems. Thesesolutions allow 3D gaming on 2D TV sets and 3D distribution on 2D support and 2D TV channels.It remains to be seen if this will lead to an anaglyphic projection revival in low-end cinema markets thatcannot afford the cost of full-3D projection systems.

Narrow-Band Wavelength MultiplexingThin-layer technologies allow for narrow-band light selectivity. Wavelength multiplexing combines twodiscrete sets of red, green, and blue light spectra that do not overlap. These spectra are currently generatedin digital cinema projection by filtering out a generic light source into one or the other sets, at a greatefficiency cost. In a single-projector system, the filter is placed on a spinning wheel inside the projector,between the light source and the imaging system (Maximus et al. 2007). In dual projection systems, thefilters can be placed in front of the lens (Jorke and Fritz 2006) (Fig. 3).

Upcoming solid-state light sources, like LED or laser beams, offer both qualities (narrow-band sourcesfinely tunable to the desired wavelength). Dual light engine projectors using such light sources will offerpassive projection that does not require active glasses or special screens.

Linear Light PolarizationIn 1929, Edwin H Land, the founding genius of Polaroid Corporation, patented the production of neutralgray polarizing filters eventually used for 3D cinema (Land and Friedman 1929). A pair of filters in frontof the projectors is matched with a pair of filters enclosed in the 3D glasses.

When a linear light polarization is used, head titling or imperfect filter alignment impairs the system’sefficiency and generates crossover. This light leak between right and left images generates an imageartifact called “ghosting.” It is considered that 3–5 % of cross-channel leaking is acceptable for acomfortable 3D experience.

Circular Light PolarizationCircular polarization is obtained by running linear polarized light through a “quarter-wave plate” thatorients it to the right hand or to the left hand. The reverse treatment is done in the 3D glasses, doubled withclassic linear polarization filters that extinguish the inappropriately oriented light. Therefore, circular lightpolarization has the benefit of not being sensitive to the alignment between the eyewear and the pro-jectors’ filters. Tilting your head will not reduce the efficiency of the 3D system. On the downside, thediscriminant factor is sensibly lower, leading to crossover levels up to 10 %. To that effect, a patentedvisual effects pass, dubbed “ghost busting,” is applied to the left and right images to pre-compensate forthe expected light leak (Lipton and James 2005).


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Combination of Multiplexing TechniquesTime multiplexing has the great advantage of requiring only one projector. Beyond the obvious monetaryincentive, it offers the additional advantage of enabling simplified adjustment to the projection system.Left/right synchronization cannot be mistaken: luminance and white balance are leveled, and keystoneand magnification corrections are not needed.

On the other hand, polarization and wavelength encoding offer advantages that cinema owners like,with glasses either cheap enough to be disposable or not needing battery and power management. In orderto get the best of both worlds, single-projector active stereo, and low-management passive glasses,vendors have developed encoders that actively polarize or filter the light output.

Such a mixed breed of active/passive stereoscopic projection has dominated the US market since therenaissance of 3D cinema in 2005, leading to widespread confusion throughout the industry. The situationmay not ease with upcoming single-projector passive projection (Sharp et al. 2010) and periscope-basedactive projection (Cowan et al. 2010). To clearly distinguish between technologies, see Table 1 inSection 7.

4000a

b

c

3500

3000

2500

2000lig

ht in

tens

ity

1500

1000

500

0350 400 450

B1 G1 R1

B2 G2 R2

500 550 600 650 700

4000

3500

3000

2500

2000

1500

1000

500

0350 400 450 500 550 600 650 700

4000

3500

3000

2500

2000

1500

1000

500

0350 400 450 500 550 600 650 700

light

inte

nsity

light

inte

nsity

wave length (nm)

Fig. 3 Narrow-bandwavelengthmultiplexing, left and right image channel spectrum (Courtesy of SD&A,www.stereoscopic.org)


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http://www.stereoscopic.org/

Tab

le1

3Dcinemaprojectio

ntechnologies

bydate

Dateof

release

Vendor

Com

mercial

name

Num

berof

projectors

Support

Stereo

Multip

lexing

Glasses

Encodingdevice

onprojector

1900s

Anaglyph

2Film

,35mm

Passive

Color

Passives

Color

filteror

coloredfilm

1920s

2Film

,35mm

Active

Tim

eActives

Synchronizedwheels

1950s

2Film

,35mm

Passive

Polarization

Passives

Polaroidfilters

1990s

IMAX

IMAX3D

2Film

,35mm

Passive

Polarization

Passives

Dual7

0mm

projectio

n

2005

–2008

RealD

Zscreen

1DigitalD

LP

Active

Polarization,

circular

Passives

Activepolarization

RealD

XL

1DigitalD

LP

Active

Polarization,

circular

Passives

Periscope

attachmentrecyclin

gpolarizatio

nloss

Sony/RealD

3D4K

/XLS

1DigitalS

XRD

Passive

Polarization,

circular

Passives

Periscope

attachmentalig

ning

and

polarizing

images

Dolby

Digital3

D1

DigitalD

LP

Active

Wavelength

Passives

Encodingwheelinside

projector

MasterImage

1DigitalD

LP

Active

Polarization,

circular

Passives

Encodingwheelin

fronto

flens

Infitec

2DigitalD

LP

Passive

Wavelength

Passives

Filter

infronto

flens

Active

glasses

Xpand,

NuV

ision

1DigitalD

LP

Active

Tim

eActives

IRsynchronization

IMAX

Digital

IMAX

2DigitalD

LP

Passive

Polarization

Passives

Filter

infronto

flens

1Film

,70mm

Active

Tim

eActives

IRsynchronization

2009

Oculus

1Film

,35mm

Passive

Polarization

Passives

Periscope

attachmentrotating,

aligning,

andpolarizing

images

Technicolor

1Film

,35mm

Passive

Polarization

Passives

Periscope

attachmentalig

ning

and

polarizing

images

2010

Deluxe

1Film

,35mm

Passive

Wavelength

Passives


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3D Screens

Polarized light multiplexing requires a polarization-preserving screen. The quality of the preservation willdictate the stereoscopic crossover or left/right channel SNR. Such screens, dubbed “silver screens,” as areference to the screens used in the early ages of the cinema industry, are now made with aluminum dustlayered over synthetic fabric.

Silver screens offer the additional benefits to have a much higher reflectance gain than classic whitescreens, allowing for more overall light efficiency within the system. The proponents of non-polarized 3Dsystems insist on the fact that this high gain applies mostly to the center of the seating area, and the patronsin the side seating enjoy a much lower light level.

Other systems, using active glasses or wavelength encoding, work perfectly on regular white cinemascreens.

Filtering Techniques

Active EyewearTime de-multiplexing is typically done with liquid crystal shutter (LCS) glasses that “blind” the left orright eye accordingly to a synchronization signal coming from the projector. Theaters are fitted withinfrared transmitters that can be placed around the stage or simply put atop the projector itself, beamingthrough the projection booth window and bouncing on the screen.

A new synchronization protocol called “DLP Link” uses the visible light domain. The glasses are fittedwith a light sensor that detects the presence of images on the screen. The assignment of the detected lightflux to either eye is commanded by an invisible light burst asymmetrically inserted in the “dark time”interval between the left and right images.

A third synchronization system, using RF signaling, is currently used in professional computergraphics (Nvidia) and consumer 3D TV systems (BitCaldron).

LCS glasses are used to be based on “Pi Cell” filters (see chapter “▶The p-Cell”), with the currentgeneration using super-twisted nematic (STN) substrates. In January 2011, a new type of LC wasintroduced, called “Electronically Controlled Birefringence” or ECB. This was used in hybrid lensesthat decode both active and polarized passive stereoscopic images (www.volfoni.com/activeyes).

Among the limitations of LCS glasses is the need for a “dark time” when no image is displayed whileone of the two shutters slowly gets back to its transparent state. Reducing this dark time to a minimum is akey issue in improving both light efficiency and color purity of LCS systems. If the dark time is notappropriately tuned between the glasses and the projector, it generates a visual artifact known as colorbanding, where smooth color gradients are seen as series of discreet flat color areas (Figs. 4 and 5).

Wide-Band Color FiltersThe best wide-band color filters are made of gelatin, as has been used for a century in stage lighting. Inaddition to being cheap to produce and easy to distribute inserted into news magazines, the widelydistributed “paper glasses” offer the best color filtering. Hard shell glasses with plastic lenses may lookmore fashionable or be more practicable for daylong use in postproduction, yet they are optically inferior.


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http://www.volfoni.com/activeyes

Tek M Pos: 4.120ms MESURES

CH3 InactiveMax

CH1Tps descente

295.0µs

CH1Tps montée

1.000ms

CH1 50.0mV 50.0mV M 5.00ms CH3 \ 2.80V60.0002Hz11–Mar–11 23:39

CH2

CH2Tps montée

1.150ms

CH2Tps descente

288.9µs

Trig�dT

Tek M Pos: 4.120ms MESURES

CH3 InactiveMax

CH1Tps descente

305.0µs

CH1Tps montée

970.0µs

CH1 50.0mV 50.0mV M 2.50ms CH3 \ 2.80V60.0003Hz11–Mar–11 23:38

CH2

CH2Tps montée

1.140ms

CH2Tps descente

305.0µs

Trig�dT

Fig. 4 Transition graph of Volfoni ActivEyes 3D glasses using electronically controlled birefringence (ECB) liquid crystalshutters (LCS) (Image courtesy: Bertrand Caillaud, Volfoni R&D)

Fig. 5 Volfoni ActivEyes are passive 3D glasses that can be turned into active glasses when connected to the ActivMeelectronic driver


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Narrow-Band Color FiltersThe Dolby/Infitec glasses are produced using thin-layer deposition technologies. Their productionprocess includes more than a dozen layers. Sensitivity to abrasion is an issue, with contrast ratio decliningover time.

Production cost has been a concern, especially for cinema owners that must buy and maintain manyhundreds of glasses for a single screen. In 2010, the glasses’ price was reduced to $17.

Polarized GlassesPolarized glasses exist in celluloid-based disposable filters and hard plastic lenses. Unlike color filters, theplastic lenses have the same efficiency as the gel-based filters. The orientation of the linear polarization iskey factor that can makes glasses incompatible between systems. Even with circular polarization, theorientation of the underlying linear filter is important to get optimal discrimination.

When 3D cinema became massively popular, the ecological impact of the high volume of discardeddisposable 3D glasses raised a big concern. Some vendors developed a recycling process that eventuallywas determined to be more costly and less eco-efficient than simply disposing of glasses. Other vendorsoffer biodegradable glasses as an alternative (Dager 2010).

With the wide use of passive 3D displays in 3D TVand 3D cinema production, a niche market exists forhigh-quality polarizing glasses. It is now possible to buy personal passive 3D glasses to be used at homeand in 3D theaters.

Summary and Conclusion

As shown in Tables 1 and 2, 3D cinema projection employs a wide variety of technologies, using varioustime and light domain multiplexing, from single and dual projectors. This technological mix and matchallows for a different solution design for every segment or niche in the market. It is also a sign that the bestbusiness model is not yet established. At the same time, film distribution channels are revisited viaalternative content distribution and extension of the digital distribution to overseas markets. Soon, newlow-cost 3D E-film solutions, based on high-end HD TV projectors, will reach the market.

The battle between active and passive solutions will be impacted by the 3D TV deployment. With hugebusiness opportunities lying in the home 3D TV market, massive budgets are currently invested inresearch and development on active glasses and full resolution passive displays. Eventually, the cinemadisplay technology will be impacted by the result of 3D TV developments. Soon, we will see new lightsources in projectors, and sooner than expected, giant flat screens will be deployed in cinema.


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Tab

le2

3Dcinemaprojectortechnologies

bymanufacturer

RealD

RealDXL

MasterImage

Dolby

LCS

IMAXActive

RealDXLS

DigitalIMAX

IMAX3D

Oculus

Technicolor

Panavision

DualSony

Dual35mm

Infitec

Stereoscopy

Tim

emultip

lexing

Active

stereo

xx

xx

xx

Collocatio

nPassive

stereo

xx

xx

xx

xx

x

Support

Digital

xx

xx

xx

xx

x

Film

xx

xx

70mm

xx

Projection

setup

Singleprojector

xx

xx

xx

xx

xx

Periscopiclens

xx

xx

x

Dualp

rojector

xx

xx

x

Light

Linearpolarizatio

no

oo

o

Circularpolarizatio

nx

xx

xo

ox

xo

o

Narrowwavelength

Com

bfilter

xx

x

Filters

Dualp

assive

filters

xx

xx

xx

xx

x

Singleactiv

efilter

xx

Encodingwheel

xx

Screen

White

xx

xx

x

Silv

erx

xx

xx

xx

xx

x

Eyewear

Activeglasses

xx

Passive

glasses

xx

xx

xx

xx

xx

xx

x

Digitalres

2K

2K

2K

2K

2K

2K

2K

4K

Film

form

at70

mm

70mm

35mm

35mm

35mm

35


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Further Reading

BitCaldron reference to be suppliedCowan M, Lipton L, Carollo J (2010) Combining P and S rays for bright stereoscopic projection. US

Patent 7,857,455Cugnini A (2009) 3D landscape still cloudy – or – anaglyph Ain’t dead, yet. http://displaydaily.com/2009/

09/28/3d-landscape-still-cloudy-or-anaglyph-aint-dead-yet/Dager N (2010) Stereoscopic 3D glasses can and should be eco-friendly. http://indiefilm3d.com/

stereoscopic-3d-glasses-can-and-should-be-eco-friendlyJorke H, Fritz M (2006) Stereo projection using interference filters. In: Woods AJ, Dodgson NA, Merritt

JO, Bolas MT, McDowall IE (eds) Stereoscopic displays and applications XIII. SPIE, BellinghamLand EH, Friedman JS (1929) Polarizing refracting bodies. US Patent 1,918,848Lanfranchi C, Brossier C (2010) Method and equipment for producing and displaying stereoscopic

images with coloured filters. US Patent 2010/0289877 A1Lipton L (1982) Foundations of the stereoscopic cinema: a study in depth. Van Nostrand Reinhold,

New YorkLipton L (2011) High brightness film projection system for stereoscopic movies. In: Woods AJ, Holliman

NS, Dodgson NA (eds) Stereoscopic displays and applications, XXII. SPIE, BellinghamLipton L, James HJ (2005) Polarizing modulator for an electronic stereoscopic display. US Patent

6,975,345Lipton L, Mayer AL, Rupkalvis JA (2011) System for the projection of stereoscopic motion pictures. US

Patent 2011/0085141 A1Maximus B, Malfait K, Vermeirsch K (2007) Method and device for performing stereoscopic image

display based on color selective filters. US Patent 2007/0127121 A1Mendiburu B (2009) 3D movie making: stereoscopic digital cinema from script to screen. Focal Press,

AmsterdamMendiburu B (2011) 3D TV and 3D cinema: tools and processes for creative stereoscopy. Focal Press,

AmsterdamNvidia reference to be suppliedReference to be suppliedSharp GD, Robinson MG, McKnight DJ, Schuck MH (2010) Stereoscopic projection systems for

employing spatial multiplexing at an intermediate image plane. US Patent 2010/0141856Sorensen SEB, Hansen PS, Sorensen NL (2004) Method for recording and viewing stereoscopic images

in color using multichrome filters. US Patent 6,687,003Starks reference to be suppliedZone R (2007) Stereoscopic cinema and the origins of 3-D film, 1838–1952. The University Press of

Kentucky, LexingtonZone R (2011) Deep screen, a history of stereoscopic motion pictures: 1952–2009


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http://displaydaily.com/2009/09/28/3d-landscape-still-cloudy-or-anaglyph-aint-dead-yet/

http://displaydaily.com/2009/09/28/3d-landscape-still-cloudy-or-anaglyph-aint-dead-yet/

http://indiefilm3d.com/stereoscopic-3d-glasses-can-and-should-be-eco-friendly

http://indiefilm3d.com/stereoscopic-3d-glasses-can-and-should-be-eco-friendly

3d cinema technology · 2017-08-23 · 3d cinema technology bernard mendiburu* vp innovation...

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