Tech

Hands-on: 3D without the glasses comes into focus at CES

We tested experimental glasses-free 3D television prototypes from Toshiba and …

Ryan Paul – Jan 13, 2011 1:46 pm | 65

Consumer electronics heavyweights are betting big on 3D technology to help drive sales of new televisions and other hardware. Aside from the considerable cost of the hardware, one of the most significant impediments to broader 3D adoption at home is the glasses.

Active shutter glasses, the dominant glasses technology for consumer-oriented 3D-enabled televisions, come with a number of serious drawbacks. They are still relatively expensive and they use batteries that have to be replaced or recharged. There are also still a number of troubling interoperability issues that prevent some active shutter glasses from being fully compatible with products from different vendors.

None of the alternatives to active shutter technology are fully competitive for the living room 3D market yet, but the industry is exploring a number of options. One approach is to move the shutter technology into the television itself, allowing consumers to use cheaper passive glasses like the kind found in theaters. RealD and Samsung, which have teamed up to pursue this approach, are calling it RDZ. A more appealing long-term strategy is to eliminate the glasses altogether—a possibility that is attracting considerable interest among hardware vendors.

At the Consumer Electronics Show (CES) this month in Las Vegas, we got our first look at some of the experimental glasses-free 3D prototypes developed by Sony and Toshiba. The products we tested ranged from portable players to full-sized televisions. We found that glasses-free technology works very well on small-sized displays, but scaling it up to big screen televisions is proving difficult for the industry leaders.

How glasses-free 3D works

As many readers probably already know, the key to creating a 3D image is to display a slightly different version of the image to each eye, such that the viewer’s brain will combine them and perceive depth. Active shutter glasses achieve this by using a technique called alternate-frame sequencing—blocking vision out of one eye at a time and rapidly alternating so that each eye effectively only sees half of the frames. In order for this to work, you need a television with a high refresh rate (at least 120hz) and you need to be able to synchronize the image on the screen with the blocking mechanism in the glasses.

Glasses-free televisions use lenticular lenses to achieve the 3D effect. Multiple images are displayed on the screen at the same time in alternating bands. A layer of of convex lenses arranged in columns is placed over the display so that the image band that is visible to the eye will differ depending on the angle. It’s similar to the technology that is used to print plastic holographic images that morph as the viewing angle changes.

Interest in glasses-free 3D was high at CES. Check out the line.

It’s important to understand that lenticular lenses make it possible to have many separate images at many different angles, not just one for each eye. This characteristic is critically important for delivering glasses-free 3D in a living room environment. The television needs to show a pair of images with different perspectives at several different viewing angles simultaneously so that everybody on the couch gets the 3D effect.

The problem with this approach is that it significantly reduces the resolution of your image, because a lot of horizontal pixels are devoted to showing the two perspectives at alternate angles. This poses a dilemma: the television needs to support the 3D effect at many viewing angles in order to make glasses-free 3D practical, but the resolution will degrade as support for more angles is added.

The viability of lenticular lense technology for glasses-free 3D will obviously be predicated on the ability of television makers to boost the resolution of their displays. Toshiba told us that their glasses-free television can handle “ultra-high definition” rendering, with a 7680×4320 resolution—four times that of a standard high definition television.

Current progress

The viewing angle limitations were painfully apparent when we tested the full-sized glasses-free 3D televisions. If you stray out of one of the sweet spots, then you will see a slightly blurred image and no 3D effect. The blurring is worse in motion-intensive scenes. We got the best results by standing directly in front of the television.

A 65″ glasses-free 3D panel from Toshiba.

Regardless of position, the whole image has a slightly reflective banded texture that we found distracting, especially when external light sources were pointed at the screen. The level of depth in the 3D imagery is also not quite as rich on the glasses-free sets. Due to these limitations, we concluded that the active shutter experience is still better, even when you have optimal viewing conditions for glasses-free.

Despite these issues, the prototypes are an impressive starting point. With further refinement and higher resolutions, the lenticular lense TVs could eventually deliver on the promise of uncompromising glasses-free 3D. Right now, it seems like the glasses-free and active shutter approaches each have different sets of trade-offs.

Toshiba told us that it intends to continue selling active shutter televisions even after it brings the glasses-free televisions to market. Consumers will be able to choose which one they want based on their own opinions about the trade-offs.

When we asked for a timeline, Toshiba said that they are expecting to launch their first glasses-free television product for consumers in the second half of the year. Sony was unwilling to commit to a launch timeline and seems to be in favor of fully perfecting the technology before bringing it to market.

Portable glasses-free 3D displays

Smaller glasses-free displays will obviously be arriving sooner than the full-sized televisions. Sony’s 3D cameras, which will be available in the near future, have embedded glasses-free 3D LCDs for viewing the captured footage and images. Sony also demonstrated a prototype of a portable 3D Blu-ray player that uses glasses-free technology. The portable player seemed much more mature than the televisions and performed beautifully when I tested it at Sony’s CES booth.

The best portable 3D experience, however, was Toshiba’s glasses-free 3D laptop. The laptop has a built-in camera in the screen bezel that it uses for face detection—it locks onto the user’s jaw-line so that it can track the movement of the user’s face. The software on the laptop can dynamically adjust the 3D rendering in order to ensure that it offers optimal 3D viewing at the angle from which the user is looking at the screen.

The quality of the 3D imagery on the laptop was excellent and the software was able to compensate for changes in the user’s viewing angle at a surprisingly fast pace. The product was extremely impressive and possibly one of the most remarkable demos that I encountered at CES. The only real problem with it is that the face detection is somewhat impaired in environments without lighting.

Conclusion

It’s clear that 3D is going to play an important role in the evolution of video consumption. Glasses-free 3D technology could help to accelerate 3D adoption by making 3D functionality more appealing and accessible to consumers. The current implementations still leave a lot to be desired, but they provide very clear evidence that the consumer electronics giants are heading in the right direction.

Ryan Paul Ars Editor Emeritus

Ryan is an Ars editor emeritus in the field of open source, and and still contributes regularly. He manages developer relations at Montage Studio.

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