Samsung LN55A950 LCD HDTV
Two of the LCD sets in this Face Off, including the Samsung, produce black levels that were unheard of in LCD flat panels until recently. Like the Sony in this group, the Samsung LN55A950 uses clusters of multicolored LEDs as a backlight, together with local dimming of the individual clusters as required by the program material. The LN55A950 is the larger of Samsung’s second generation of LED local-dimming sets.
Samsung calls its version of local dimming LED Smart Lighting, and it promises to dramatically improve the black levels and contrast in LCD sets. Until now, those have been the two significant shortcomings of LCD technology. Unlike the Sony, which uses red, green, and blue LEDs, the Samsung’s LEDs are all white, with the primary colors provided by filters. Samsung argues that its design offers technical advantages, like lower power consumption.
The Samsung’s inputs are divided between side and rear jack panels. It offers all of the usual inputs, including four HDMI 1.3 and two component video, plus a LAN connection for a home network.
The set has three preset picture modes: Dynamic, Standard, and Movie. Two additional modes, Cal-Day and Cal-Night, are offered onscreen only when they have been calibrated in the service menu.
Apart from the standard picture controls, the only controls I used regularly were Backlight, Gamma, Color Space, White Balance, Color Tone, and LED Smart Lighting. The Warm2 Color Tone setting was unusually accurate out of the box in the Movie mode. However (as with all the sets), I performed a full calibration prior to the group testing. The set offers an extensive set of color adjustments in the user menu, including White Balance (red, green, and blue at the top and bottom of the brightness range for color temperature tweaking) and Color Space (for fine-tuning the color points in the Custom setting). The set is also the only one of the four to offer a Blue Only mode—a big plus for properly setting the color control.
Like most new high-end LCD sets, the Samsung operates at a refresh rate of 120 Hz and includes two separate features designed to compensate for LCD motion lag: Auto Motion Plus 120Hz and LED Motion Plus. You can use them together or separately.
If Auto Motion Plus 120Hz is turned off, the display repeats source frames as needed to reach the set’s 120-Hz native operating frequency. (For example, it will repeat each frame in a 24-Hz source five times to reach 120 Hz.) If you turn Auto Motion
Plus 120Hz on (there are Low, Medium, and High settings), the display adds the same number of frames, but it interpolates them from the preceding and following frames.
LED Motion Plus cycles horizontal blocks of the LED backlights on and off, scrolling from top to bottom once every frame (120th of a second). Since this shuts off the backlighting while the LCD is changing states from on to off or back, you don’t see the lag that occurs during this transition. But the technique also noticeably reduces brightness.
As noted in the introduction, we left both of these features off for the test.
We did a full review of the LN55A950 in our December 2008 issue, and you can find more information about it there. But there is an important difference this time around. In that review, I reported that the Samsung’s screen went completely black with a full-screen black image (such as a full fade-out), some of the backlight zones covering the darkest areas of the picture went completely dark on the darkest program material, and the less dark areas stayed suitably bright. This may seem desirable (and is, in theory). But in this case, it produced an odd spotlit effect, likely due to the necessarily limited number of backlight zones. Samsung provided us with some service menu settings that greatly reduced this problem but didn’t eliminate it.
Samsung loaned us the same LN55A950 sample for this test, but a board had been replaced. In theory, this should have been a complete fix for the problem. It did cure the problem, but it also raised the set’s minimum black level. The Samsung’s screen no longer goes completely black with a full-screen black image (unless you crush the blacks by dropping the Brightness control two to four steps below its optimum setting).
The set’s blacks are still excellent by measurement. But rather than having the lowest absolute black of any of the four sets in the test (which it would have had prior to the board change), it came in third with the judges in the black level scoring.
The Samsung’s HDMI 1080i-to-1080p video processing, in HD and SD (with our standard battery of tests) was uniformly good to excellent. It also passed our current series of tests for 3:2 pulldown. The component 480i-to-1080p video processing was similarly good to excellent, apart from a poor result on a mixed source (a video scroll over a film background).
The Judges Speak
While the Samsung’s black level rating did manage to best the Panasonic for second place (the Sony and Pioneer tied for first), its shadow detail ratings pulled it down. One panelist commented that even directly on axis, the dark scene from The Incredible Hulk looked too dark and lacked detail. He found the black areas in the shipping-crate scene from Madagascar to be medium gray. He also said the dark scenes in the other material were either too light (even sitting directly in front of the screen) or, again, lacked detail. Another judge thought that the Samsung’s blacks looked elevated on all the clips, without a lot of shadow detail. A third found its shadow detail to be the worst of the group.
But the criticisms weren’t universal. One judge was impressed by the Samsung’s absolute blacks and thought that the differences between the Pioneer and the Samsung were less than expected on some material (on axis at least). But he also noted that on mid-dark scenes, the Sony and Pioneer looked better than the Samsung.
On axis, the comments on the Samsung’s color were generally favorable. While one judge remarked that he saw fewer gradations in the bright Madagascar colors than on the other sets, another remarked on how well the colors popped on this selection. Others liked the on-axis color as well. One observer commented on how accurate it looked on Hidalgo. Another liked that it had more intense oranges and reds than the Sony offered. Another wrote favorably about the Samsung’s fleshtones (no one criticized them). But the on-axis/off-axis issue raised its head again in the color department. One panelist remarked that it “lost color tone even a little off axis.” Another mentioned the off-axis washout, although she thought the Sony was worse in this regard.
Several of the panelists commented on a bit of motion blur, but none appeared to find it bothersome. One thought that the SD clips from Shakespeare in Love had the most motion artifacts. But the panel praised the “rich, crisp edges” on Hidalgo, as well as the detail on Alex the lion’s mane in Madagascar. Another commented on Hidalgo as well. “Wow! A little more dimension and pop than the Pioneer, but the Pioneer revealed film grain better,” he declared. And from another, “Great detail, just like the others. There was very little softness to any of the clips, and the high-def stuff looked fantastic, especially the brighter stuff and the animation.”
Having viewed the Samsung extensively in the pre-test setup process and when I reviewed it for the December 2008 issue, I was surprised by how much criticism it drew for black level and shadow detail. As for its absolute blacks, it was clearly at a disadvantage next to the Sony and Pioneer. But the measurement section shows it still turned in a very impressive pure black level of 0.003 ft-L, far better than most flat panels can manage. Some of the negative comments were clearly triggered by the mixed messages sent by this set’s on- and off-axis performance.
Another reason for the below-average (for the group) black/shadow detail ratings may have been the recent changes Samsung made to eliminate the black level issues I reported in the December 2008 review and repeated briefly here. The panel’s comments might also simply have reflected a preference for slightly higher brightness settings than the one I chose for this test, particularly among our casual viewers. (Or a lighter gamma. We used the Samsung’s default middle Gamma setting.) Given the company it was in, we felt the best setup should maximize the deepest black performance within the small range of correct brightness control settings (which in this case was three steps, maximum, from lowest to highest). Many viewers prefer higher brightness settings (sometimes even well above the proper level) and want to see every last bit of shadow detail—even if it washes out brighter scenes.
I suspect that the most significant differences the panel saw between this set and the similar Sony might simply lie in some additional factory tweaking of its near-black performance. These may be very slight. Small differences in a set’s absolute black level and in the rate at which it comes out of black (the near-black gamma) can make a huge difference in perceived performance—and viewer preference. There were no losers among the sets in this group, and it’s very possible that some additional factory-level work on the Samsung’s service menu settings would have improved this set’s standing with some of our judges.