Samsung UN55B8500 LCD HDTV
Back to the LED Future
Samsung, it appears, is going LED in a big way. Thirteen of its LCD sets in the 6, 7, and 8 Series use LEDs for back-lighting instead of CCFLs (cold cathode fluorescent lights), which until recently have been nearly universal in flat-panel LCD HDTVs.
While LED backlighting offers the potential for improved color performance, more uniform screen illumination, thinner sets, and less power usage, its biggest advantage is that LEDs can cycle on and off almost instantaneously. With the right implementation, this capability opens the door to dramatically improved black levels.
The technique is called local dimming. Not all LED-backlit sets are local dimmers, but two of the new Samsungs are. At the top of the pile is the 55-inch UN55B8500.
Samsung was the first company to market LED local-dimming designs. We had a look at the first generation (the LN-T5281F) back in April 2008, and the second generation (the LN55A950) in November 2008 and again in a four-set Face Off in February 2009. On each occasion, these sets made a profound impression on us, delivering black levels that we never dreamed possible in an LCD design. The opportunity to spend quality time with the third generation, which incorporates all of Samsung’s refinements of the technology into its current flagship set, was a no-brainer.
By themselves, LCDs produce no light, which is why all LCD sets require backlighting behind the LCD panel. The individual LCD pixels in the panel simply act as gates, which either pass or block the backlight’s illumination as the source image requires. But LCD’s ability to block light is limited. Some of it always leaks through, even when the image calls for total black. That’s why LCDs traditionally have mediocre black levels and shadow detail.
However, by using LEDs as backlights, a new wrinkle is possible. Since LEDs can be turned on or off and can be arranged in individually addressable zones or clusters behind the screen, it’s possible to selectively dim or darken different parts of the screen to match the light and dark areas of the picture being displayed. It’s still the LCD panel’s job to produce the actual image at the pixel level. However, by selectively dimming the individual LED zones, we can help the LCDs overcome their light-blocking limitations and provide a contrast level that even the best conventional LCD displays can’t offer. This process is called local dimming or, in Samsungese, Smart LED.
Of the 13 Samsung sets that use LEDs for backlighting, only two—this one and its 46-inch sibling—employ local dimming. The rest control all of their LED backlights simultaneously.
While the UN55B8500 may not be the slimmest set in Samsung’s stable, at 1.6 inches thin, it isn’t far from it. And at 78 pounds with its rotatable stand, you won’t have to corral a pair of NFL linebackers to unpack it and set it up. Two average couch potatoes will do.
The Samsung has four selectable picture modes, and they’re separately adjustable for each input. I did my testing in Movie mode with appropriate settings for the most accurate picture. It also has hidden Day and Night modes that a calibrator can adjust in the service menu, lock (if desired), and activate so they appear as user menu selections. (They are not ISF modes; Samsung hasn’t signed up for ISF certification.)
The set offers the usual video controls, including a 10-step backlight adjustment. I never got above a setting of 5, and I rarely set it that high. I stayed mostly at 3 for night viewing in a darkened room and 4 for daytime viewing.
The Advanced and Picture Options menus offer additional adjustments. Some are useful, while others are best avoided. The latter include Dynamic Contrast, Flesh Tone, and Digital NR (you won’t need noise reduction with a good source).
The Black Tone control, with Dark, Darker, and Darkest set-tings, appears to be one of these avoid-it adjustments as well. However, I found that in its least aggressive setting (Dark), it subtly improved the image on some programming and didn’t clip the blacks.
A Blue Only control (available only in the Movie and Standard modes) turns off red and green. This lets you set the color and tint without resorting to color filters, which can be inaccurate on LCD sets.
There’s also a seven-step Gamma adjustment, a Color Space control (with a full set of adjustments to fine-tune the color gamut), and White Balance controls (both high and low for all three primary colors).
In my last Samsung review, I dismissed that set’s Edge Enhancement control. But we live and learn. On the UN55B8500, this adjustment had a subtle yet positive effect on the image, with no visible white-line enhancement or other artifacts (when the Sharpness control is set correctly).