Sony's upcoming XBR-84X900 4K TV produced beautiful images in a demo at the IFA trade show last week, but its size, likely high price and a lack of content that can take full advantage of the set makes it an unlikely buy. See also Group test: what's the best TV?

Sony and a number of other vendors showed so-called 4K TVs. The name comes from their horizontal resolution of almost 4,000 pixels: they have a resolution of 3,840 by 2,160 pixels, four times the number of pixels found on HDTVs, which have a resolution of 1920 by 1080 pixels.

It is easy to get carried away when seeing a 4K demo: the Sony XBR-84X900 4K TV set produces a 2D image that, thanks to the higher resolution, feels almost as immersive as a 3D image.

But demonstrations at trade shows such as IFA hardly give a balanced view of how a product performs under normal circumstances. All the 4K demos, not just the Sony XBR-84X900 4K TV's, used slow-moving, bright images, which are the least challenging to reproduce.

While it is easy to be impressed by the images, it is also easy to see why 4K TV sets will initially have an uphill battle for a place in the market.

The two main challenges facing them are their price and the lack of native 4K content.

Sony hasn't announced a price for its XBR-84X900 TV, but LG Electronics' 4K TV will cost about US$22,000 when it starts to roll out in North America, Europe, Asia, and Latin America starting in September.

The lack of content also has to solved before the 4K format can take off.

Movies are already shot or the analog film scanned to accommodate 4K, but when they will be available to consumers in that format remains to be seen. Broadcasters would have to upgrade their whole production and distribution infrastructure before TV shows can be broadcast in 4K. At present, on-demand distribution over fiber networks seems to be the likeliest option.

Sony intends to get around the lack of native content by having its TVs upconvert HD content such as that on Blu-Ray Discs to 4K format on the fly. It's the same process HDTVs use to display standard-definition images on high-definition screens.

In a back room at its stand, Sony had two units on display next to each other. During a demonstration, Sony displayed 4K content on one and upconverted 1080p content on the other, and the results were barely distinguishable.

The best result will come when upconverting content that was originally mastered in 4K, while results won't be as good for sports broadcasts, a Sony spokesman said.

The last challenge is that to see the difference between 1080p and 4K you need a big screen. How big depends on who you ask, but Sony's TV is 84 inches, which won't be a good fit for everyone.

Sony XBR-84X900: Specs

  • 84in LED-LCD
  • 3D Passive 3D
  • Built-in Wi-Fi, Ethernet
  • Smart TV
  • 4K X-Reality PRO with up-conversion
  • LED Backlight technology
  • Edge-lit with local dimming
  • Native resolution 3840x2160
  • Refresh rate 240 Hz
  • 84in LED-LCD
  • 3D Passive 3D
  • Built-in Wi-Fi, Ethernet
  • Smart TV
  • 4K X-Reality PRO with up-conversion
  • LED Backlight technology
  • Edge-lit with local dimming
  • Native resolution 3840x2160
  • Refresh rate 240 Hz

OUR VERDICT

The Sony XBR-84X900 4K TV produces stunning images, but we won't be rushing out to buy one until the price drops and there is more content that can make use of its capabilities.

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