The ultimate deciding factor for a flat-panel TV is, of course, the picture quality. In this chapter, we'll describe in detail how well the UE 40 B 7090 really performs in terms of contrast, black level, sharpness, and signal processing. We'll also back up our results with measurements from our test laboratory.

Contrast and Black Representation:

This diagram shows the contrast ratio in various picture modes and using various measurement methods.

To give an impressive picture in dark movie scenes, a TV has to have high contrast and deep blacks. Otherwise, it takes all the fun out of home-theater - night scenes look flat, and blur into a tepid fog - you might know the effect from an old flat-panel TV or projector. This is almost certainly to do with a low contrast ratio.

The Samsung masters night scenes well, but not outstandingly. With the optimal picture settings (see Ideal Settings), it produces a contrast ratio within a picture (the "in-picture" or "native" contrast) of around 1,700:1. For comparison: today's best LCD TVs reach up to 3,000:1, good plasmas even more. Examples of contrast-masters include the Sony KDL-55 X 4500, which is an LCD with localized backlight adjustment ("local dimming"), or plasma-supernova the Pioneer KRP-500.

The Samsung uses two tricks to make its picture look richer than its measured contrast values suggest. Firstly, the glossy front panel gives a considerably stronger depth-effect and radiance than matte-finish displays - this is the same effect as glossy photo prints.

For its second trick, the Samsung automatically turns down its backlight in dark scenes (known as "dynamic backlight modulation"). The technology reacts quickly and strongly: We see it as a benefit, although many video purists would rightly criticize the lack of an option to turn the modulation off. One disadvantage of technologies like this is that dark picture-details differentiate less if you're watching in daylight.

In consolation, the backlight modulation increases the Samsung's so-called dynamic contrast. If, for example, an almost completely black shot of outer space is followed by a gleaming shot of an exploding supernova, the flash of light shines up to 38,000 times brighter than the preceding black image.

With this checker-board test pattern, we determine the so-called ANSI contrast. This value is a measure of how strongly white areas of a picture brighten up nearby black areas. The higher the checker-board contrast, the more intense black and white areas of a picture will look.

On the Samsung, white areas shine around 389 times brighter than black ones, giving an ANSI contrast of 389:1 - an impressive value. Very few TVs break the 400:1 barrier - among those that do is Sony's LCD TV the KDL-40 W 5500, which measures 433:1.

Black Level Test:

This black test pattern shows how strongly a TV continues to shine when supposedly displaying pure black - experts refer to this as the black level. Theoretically, a black image should appear perfectly black whether viewed in a light or dark environment, but almost all TVs allow some light to leak through from the backlight.

Several factors affect how strongly the viewer perceives this residual illumination: For example, how strongly external light brightens up the screen (not much with LCDs, but quite strongly with plasmas), how high the TV's contrast ratio is, and how strongly the intensity of the residual illumination depends on the picture's contents.

Thanks to backlight modulation, the Samsung produces a deep black. Depending on whether the picture is completely black or contains small white areas, the black level varies from 0.05 cd/m2 to less than 0.01 cd/m2 - even good plasmas such as the Panasonic TX-P 42 GW 10 cannot beat these values.

But it's not really fair to compare these values. On the Samsung, blacks have a tendency to look dark blue and to brighten up when viewed side-on. Unlike a plasma TV, this LCD can only achieve a low black level by turning down its backlight.

Viewing Angle Dependence:

This diagram shows how picture quality varies with viewing angle.

Ideally, we would see a circle. The more club-shaped the diagram looks, the more strongly the picture quality depends on the viewing angle.

Typically LCD: Within a narrow region of around 10 degrees left and right of center, the picture quality is almost constant. If you get the unlucky seat at the end of the sofa, however, the quality you see drops significantly: The picture becomes darker and loses contrast, and blacks become dark blues.

Even at a viewing angle of just 30 degrees, around two thirds of the contrast is already lost. To enjoy deep blacks on the Samsung, you really have to be sitting in the center of the picture. Every LCD we know has a similar problem - only traditional tube TVs or plasmas display a great picture at wide viewing angles.

Video Processing of Standard Signals:

Resolution test pictures tell us about a TV's sharpness and fine-detail reproduction. The test picture above judges sharpness and fine-detail reproduction in the horizontal direction. Other test pictures - not shown here - help us evaluate sharpness in the vertical direction, and show how finely the TV processes colored details.

Video Connections:
Like every modern TV, the Samsung offers a range of video connections. The following applies as a basic rule: Use HDMI wherever possible - this is the only sure way to transmit picture and sound to the TV in top digital quality. But, since not all consumer-electronics devices use this interface yet, the TV's analog video connections continue to be significant.

Scart and YUV:
Via Scart - important in Europe - the Samsung produces an accurate, pleasantly sharp picture. The TV also has a YUV connection, also known as component video. This should actually produce excellent levels of fine detail, since YUV is the highest-quality analog video-connection and can also transmit HDTV signals. But, in the 576i and 576p resolutions, the Samsung's YUV picture is noticeably less sharp than the excellent HDMI picture, making the image appear softer.

De-interlacing:
Conversion of interlaced pictures to progressive pictures ("de-interlacing") works well on the Samsung for both film- and video-based recordings. The camera pan across the beach is accurate in the tricky test scene we often use from "Six Days Seven Nights". Only the most finicky of scenes cause line-flicker: in "Space Cowboys", for example, there's brief flicker on Clint Eastwood's glasses-frame or on the finely structured picket fence in chapter eight. We use a range of these scenes to evaluate various aspects of a TV's picture quality - for more examples, see our Picture Quality Testing article.

Like most TVs, the Samsung crops the edges off input signals to an unnecessary degree; the overscan amounts to as much as 20 percent, depending on the type of signal, meaning five percent of the picture is missing on each of the four sides. This makes the image larger, and its quality lower, since the screen contains less picture information.

Via Scart, the Samsung crops around 40 pixels at both the left and right edges, as well as 20 and 13 pixels at the top and bottom edges respectively. With HDMI-576i, the overscan still claims 30 pixels at each side and 15 pixels at the top and bottom. Only HDTV signals display fully.

Video Processing of HDTV Signals:

The Samsung processes HDTV material outstandingly well. Even fine checker-board patterns in full HDTV resolution (1,920 x 1,080 pixels) appear in perfect detail on the UE 40 B 7090, whether the picture arrives in 60i, 60p, or 24p format. Likewise, Blu-ray blockbusters such as "I, Robot" or "Spider-Man 3" display crisply and with a high degree of detail.

The UE 40 B 7090 sailed through the test-pattern obstacle course with just one small anomaly: In certain test patterns, saturated greens look a touch too light in comparison to other colors. With movies, however, this isn't visible - color processing is essentially accurate for SDTV and HDTV sources.

Blu-ray Playback:

When playing back movies from Blu-ray, the Samsung shows motion as you see it in the movie theater. The 24 motion phases of the film-based recording appear accurately and without the irregular stutter that some TVs show. A good example is the Blu-ray movie "Casino Royale", where the animated playing cards in the opening titles glide across the screen with the intentional, regular judder that you see at the movies.

Excellent: The video processing recognizes when it is dealing with film-based material even for 60-Hertz input signals (60i/60p). It then plays back each motion phase individually as if the signal were in 24p format. This sophisticated technique is known as "inverse telecine".

Signals in 60i format (60 frames per second, in the interlaced mode) present a further challenge: The TV must also de-interlace the pictures - that is, convert them into individual pictures that each contain the full number of horizontal lines. The Samsung handles this well, as you can see in the fourth chapter of the Bond movie "Casino Royale": The decorative stripes on the sea-plane show no flicker, unlike on some other TVs.

Tuner Picture:

In MOVIE mode, the analog TV picture shows natural colors, low noise, and decent detail reproduction. But the Samsung lacks some of the finest details when compared directly with Panasonic's TX-P 42 GW 10 plasma-TV, whose tuner displays an excellent picture.

For digital reception, picture sharpness is better than for analog; in particular with digital cable reception, the Samsung displays a very clear and detailed picture. The aforementioned Panasonic still comes up trumps, however, delivering a yet-finer picture.

Picture Uniformity and Digital Picture Errors:

With conventional LCD TV, the backlight covers the entire area behind the liquid-crystal panel. On the Samsung, backlighting comes exclusively from the LEDs in the frame. This presents a tough challenge, since the light must illuminate the whole picture uniformly. But the South Korean engineers have done a top job - slight variations in illumination only become visible with special test pictures that fill the screen. What's more, conventional LCD TVs can't do any better.

Fast motion is passable on the Samsung. Initially, we tested the picture without the 100Hz MOTION PLUS setting: With the backlight set to full strength, the picture blurs in fast camera pans - this is fairly normal behavior for an LCD TV. With the backlight turned down, the blurring effect disappears, and fast-moving objects appear with a crisp, but tripled, edge. With movies, which contain less motion-information than video, fast movements look crisp and compare well with the LG 42 LH 7000, for example.

Video Material and 100Hz MOTION PLUS:
Video material simply doesn't impress without 100Hz MOTION PLUS. Fast-moving objects judder slightly, like we're used to seeing in movies. Our tip: Use 100Hz MOTION PLUS in the SMOOTH setting for video material - this provides fluid motion with only slight blurring.

In comparison to the motion-enhancement technologies from Sony or Grundig, the Samsung shows relatively strong artifacts, especially with tricky test patterns, in the form of pixel-noise and block-artifacts around moving objects. With movies, we recommend turning off 100Hz MOTION PLUS, since this has more pronounced side-effects for movies than for video material, and eliminates the classic movie look (regular judder).