LCD TV Reviews

LEDs that are positioned behind the screen in small clusters of red, green, and blue devices (or white LEDs with suitable filters—Samsung’s approach) have an advantage over CCFLs in that you can easily dim them or turn them off. This has led to the development of LED sets with local dimming. In such sets (currently in only a handful of models), the LEDs are dimmed by zone in response to the characteristics of the source. This can deepen the blacks where needed without dimming the brighter areas of the image.

So what’s with this LED edge-lighting thing? Apart from the cost (LED backlighting requires a lot of LEDs), one significant problem with behind-the-screen backlighting is that it limits how thin the set can be. The super-thin set manufacturers think the public wants a new approach. If the backlighting can be placed along the edges of the screen and directed where it’s needed, thin can be in. This is hard to do with CCFLs, but LEDs are ideally suited to this approach.

The UN55B7000 uses LED edge-lighting technology. While true local dimming isn’t possible with this design, edge lighting lets you control the overall screen illumination more easily than with fluorescents. Samsung’s descriptions don’t mention it, but my observations indicate that in order to deepen the black level and the dark grays, the UN55B7000 does overall dimming to a degree. In fact, there were times when the Samsung’s screen faded to total black between scenes. However, this was rare, and it depended on the video settings. Most of the time, with the set adjusted correctly, it simply dropped to a much deeper shade of gray than you’ll see on conventional LCD sets.

The UN55B7000’s edge lighting doesn’t provide completely uniform illumination, but this was only noticeable with a totally black, full-screen image in a completely dark room. In that situation, the edges and corners of the screen, while still respectably dark, were noticeably lighter than the center. I never noticed uneven screen illumination on normal program material.

I found it tricky to get just the right combination of Brightness, Gamma, and Backlight settings to squeeze the best from both the light and dark scenes. This may be because of the way Samsung modulates the LED brightness in dark scenes. You can’t defeat this modulation, but there was only one occasion in weeks of viewing when I saw what looked like visible pumping. I finally settled on Movie mode at a Gamma setting of 0 (occasionally –1 or +1). A brightness setting of 47 was technically the most accurate, and it produced the deepest black level. A setting of 49 sacrificed blacks a bit, but it worked better with some sources. I never felt the need to exceed a Backlight setting of 3. Of course, other samples may give slightly different results.

With that done, the UN55B7000’s black level and shadow detail were superior to those from any other LCD I’ve tested, apart from local-dimming designs. This gives the images a light-to-dark consistency that’s rare in LCDs. Only on the darkest and most chalenging material (scenes that give almost all video displays palpitations) did I see a hint of the grayish, foggy look that impacts LCDs more than any other type of display.

The Samsung handled most of my standard tests for rich, deep blacks and shadow detail exceptionally well. In my experience, the darkest scenes in Master and Commander: The Far Side of the World (chapters 2 and 12), Stargate: Continuum (the opening titles sequence and chapters 3 and 21), and Madagascar (chapter 6) have only been handled better by local-dimming sets, the best Pioneer KURO plasmas, and a few projectors.

The Samsung’s color was also superb. It was vivid when it needed to be and more subdued when that was appropriate for the source. A striking example of vividness is Curse of the Golden Flower (Blu-ray). While I’d never rave about the transfer’s resolution (it’s slightly soft), the colors in the sets and costumes are perhaps the most over the top I’ve ever seen, with reds, golds, and yellows running wild throughout the film.

The Samsung simply told it like it was, which was clear from the far more natural tones in Seven Years in Tibet. The latter not only showed off the Samsung’s refined color palette, it also demonstrated the set’s superb resolution. This is one of the best discs available for bringing out all of the film’s fine details, from Brad Pitt’s acne scars to the threads in the period Tibetan costumes.

The Samsung’s performance is so striking overall that its single weakness is all the more obvious. As you move off center, the picture begins to degrade. It’s fine for two people on a couch or for three who are either very friendly or not too fussy. But if you move much more than 25 or 30 degrees off center, the black level begins to rise dramatically, which destroys the contrast ratio and bleaches out the set’s gorgeous on-axis color. One word of shopper’s caution: This issue will always be less visible with the super-bright picture settings used in a showroom.

Conclusions
If the last paragraph comes across as a bit of a downer, I must say that the Samsung has a lot of company here. Off-axis image deterioration is an issue with most LCDs, and it’s probably the last serious weakness of LCD designs now that their black levels (in the best sets) have improved dramatically.

However, the Samsung does not have a lot of company when it comes to its combination of outstanding and accurate color, deep blacks, fine shadow detail, precise resolution, and exceptional video processing. If you’re looking for a first-rate LCD set but can’t quite stretch your budget to cover a local-dimming design (a local-dimming Samsung of the same size goes for $5,000, a Sony for $7,000), this set deserves a very close look.