Pros And Cons

None of the systems mentioned is perfect. In fact, it's safe to say that they all have trade-offs, either in terms of image quality, comfort or expense. With the sequential systems, as pushed by Panasonic, Mitsubishi and Samsung, comfort and expense clearly come into play when you consider that you'll need to wear the glasses whenever watching 3D content, and that the glasses - which need to be powered and synchronised with the screen using an infrared or wireless connection - will inevitably be expensive. What's more, with the glasses comes some perceptible loss of brightness; not a disastrous loss, perhaps, given the extreme levels of brightness possible with upcoming plasma or LCD displays, but it's there nonetheless.

Active shutter glasses, like the Xpand glasses used in recent Panasonic demonstrations, provide a clear image in more lighting conditions, but will be more expensive than passive glasses to buy and maintain.

With the polarized, passive glasses systems, as being produced by LG and Hyundai and demonstrated by Sony, the comfort and brightness issues remain. On the plus side, however, passive glasses are much simpler to produce and more affordable than active shutter glasses, and they don't require power or any form of synchronisation. As a result, systems and spares should be more affordable. The trade off with is that the screen is interlaced, with alternate horizontal or vertical lines displaying left or right eye views of the image, and that this in turn means that you're only getting half the resolution in the relevant axis. In effect, you're moving from a 1,920 x 1,080 image to a 1,920 x 540 image, and while this can still seem sharp, you're not getting the full 1080p 3D image. It's interesting to note that Sony's CES 2009 showcase system, which appeared to use polarization in concert with a pair of RealD glasses, has only been described as an exploratory project designed to gauge interest, so it's unlikely that Sony has committed to this technology yet.

Obviously, the strength of the lenticular system being promoted by Philips, Toshiba and LG is that it gets rid of the need for glasses altogether, and the lenticular lens sheets used on top of the LCD panel are relatively inexpensive to produce. However, the trade-off is once again resolution. For every view available from a lenticular 3D display, you lose a direct portion of the screen's resolution. For example, the actual resolution of a nine-view display would be one-ninth of the resolution of the actual display.

Philips cleverly gets around this by interlacing the views diagonally rather than horizontally or vertically, which creates a larger perceived resolution (plus the move to 3D does, apparently, lessen the effect). However, even taking this into account Philips admits that moving from 2D to 3D across a range of views effectively means stepping back from HD to SD resolutions. This is partly why Philips is now touting QuadHD; a next-generation display with double the horizontal and vertical resolution of 1080p.
Sony has demonstrated a system using polarization and RealD glasses, but has yet to commit to any specific standard.

What's more, the lenticular technology itself has other issues. While the sweet spots have become larger, the technology still doesn't work from any given angle, so if your living room isn't set up for the sweet spots, you'll have trouble getting full benefit from the system.

Note, too, that all these systems are tied into the manufacturer's TV technology of choice. Panasonic, Samsung and Mitsubishi, for example, like the sequential system because it works with, respectively, the high-end plasma and DLP projector technologies being used in their high-end screens. Philips, LG and Sony, in turn, might well be attracted to lenticular or polarized/passive technologies because they are a more natural fit for LCD screens. In the end, it seems likely that we can expect to see a combination of technologies enter the market and compete. We'll then be able to evaluate the pros and cons of each, and spend our money accordingly.

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