Wednesday, December 15, 2010

Dolby Digital 3D vs Real D / Master image systems.

It's interesting to watch this evolutionary battle play out.

Dolby 3D Digital Cinema / INFITEC Glasses

VS.

Real-D / Master Image Circular Polarized Glasses

Dolby's 3D is clearly superior, I mean just breathtaking 3D, but in the end it's the costs and not just the image quality that may end up determining the winners in this game.

Glasses

I am told the Dolby glasses are $38 a pair, which is an amazing deal for 2 precision interference filters.

The Real D / Masterimage system using inexpensive plastic polarizers. This make them almost disposable.  But this lower cost in glasses comes at a cost.

 
American Paper Optics Even make disposable paper glasses for 3D movies that I am sure the theaters really have consider deeply.  I think they went for the recyclable plastic just because the paper seemed too cheap.

I wonder if they ask their customers, "Would you like that in paper or plastic?"



There is also a shutter goggle system that nearly identical to what they are now pushing with 3D HDTV's. These are my least favorite as they require batteries, and are bulky and don't work 1/2 the time.  I have not seen these use in a normal theater setting ever, only in amusement parts, older IMAX system and trade show demos.

It's getting push with HDTV's only because it required no changed to existing TV designs and they can charge more.   Just the addition of an IR LED to provide a sync signal to the glasses and a sticker and double the price. I will discuss shutter goggle technology in more depth in a later article.


Screen

3D projection using polarization requires non-depolarizing screens. What this means in that the screen must be coated with a special polarization preserving material, usually silver or aluminum metals in paint.

Regular white matte theater screens cost normally around $6000 for an ordinary screen which the Dolby system and shutter glasses can use.

But not just any screen will work with polarized light it cost $13000 or more for an old fashion silver screen or specialized 3D Polarization preserving screen.

Da-Lite 3D Silver Matte or Virtual Grey front projection material

Silver screen in general don't give as good of an image as the high reflectivity white matte plastic screens.  You can see an almost metallic luster and they have more of a Grey appearance.


Maintenance

But there is a hidden cost with the Dolby system, with the increased cost of the glasses this brings about several other problems.

The need to keep to employees by the theater doors when the film ends to collect the glasses even with the anti-theft RF tag.

Also the cost of washing and sterilizing the glasses and the manpower needed to do this.

When they recycle the polarizing glasses the issues are the same they can order many pair of glasses and eat the cost of the ones that aren't returned.

The glasses can be sterilized in one of two ways.
1.) UV sterilization system but most UV sterilizers are only small capacity and usually used for laboratory safety goggles.

2.) A commercial washer that uses a special disinfectant detergent.

Both take about 1 hour and some man power to load and unload the glasses.

 UV sterilizer

Projectors & Filter Wheels.

Both systems use synchronized wheels in front of a digital projector.

In the Dolby system they provide now is a sealed Barco SUPERKONTRAST projector system with the filter wheel inside. The Theater operators can not open it and if they do an Alarm system prevents the projector from running till a technician comes out and resets it.

Dolby 3D filter wheel


JDSU is the world's largest producer of optical coatings, developed the 3D filter wheel technology for use in an exclusive partnership deal with Dolby.

I just can't tell you how cool this technology is. Some of the most impressive optical interference filters to split the RGB into and upper and lower spectrum for each eye. 


Master Image also has a rotating wheel system, with alternating Clockwise and Counterclockwise circular polarizers.

I see is both of these as some sort of throwback to the film days with all the the clockwork and moving parts.


The Real D system uses "Z Screen" basically an electronic polarizing filter but for the most part is 100% compatible with the Master Image system.







Summary


$38 Glasses, expensive to clean
Uses existing screens
Special Projector, cost unknown.
Needs special digital cinema server.


Glasses almost disposable. They are recycled, meaning washed and repackaged.
Needs special screen at 2x the cost.
Can use any standard projector and digital cinema server.



Glasses almost disposable. They are recycled, meaning washed and repackaged.
Needs special screen at 2x the cost.
Can use any standard projector and digital cinema server.



$50+ Glasses, expensive & difficult to clean, (can't get electronics wet),
The glasses are also prone to malfunction, with batteries dying, contact failing etc.
Uses existing screens
Can use any standard projector and digital cinema server.


OPINION

It's my opinion that even though the Dolby system is superior, the circular polarized systems will win, the glasses are lighter, cheaper and disposable. (really important with small kids)

I think in the end they will also win the battle on the HDTV front also for this very same reason.



More Reading:

I explain in some depth how the Dolby system work here.
Dolby 3D Digital Cinema
MasterImage site
Chinese source for Circular Polarized glasses

Eye Wear

Through the 3D looking glass

http://www.avsforum.com/avs-vb/showthread.php?t=953978&page=5


http://www.reald.com/

3D projection in cinemas

Digital 3D-Systems

American Paper Optics

Dolby 3D Glasses Training Video

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