Picture Quality in Detail

 

 

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 Panasonic TX-P 42 GW 10 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:
The Panasonic greets the user with a gamma setting of 2.0 - this is too bright, and makes little sense given the powerful contrast of this twelfth-generation panel. Your very first step should therefore be to set the gamma to the darker 2.2 characteristic in the "Advanced Settings" menu. When measured, this actually produces a value of nearer 2.3, which suits the contrast-rich screen excellently.

We only recommend using the darkest gamma setting, 2.5, in the evenings, in a fully darkened home-theater; during the day, it'll only make pictures look gloomy. Be careful: If you accidentally press the N button on the remote control, the Panasonic switches back to the factory settings, with the brighter 2.0 gamma characteristic. If, therefore, you notice something change suddenly in the picture, you should check the gamma.

 

Contrast Ratio:

 

 

This diagram shows the contrast ratio of the Panasonic TX-P 42 GW 10 in various picture modes and using various measurement techniques. We could only marginally improve the "Cinema" mode through fine-tuning (see the "Colors and Ideal Settings" section below). The TV then delivers outstanding results, namely an ANSI contrast of 463:1 and an on/off contrast of 3,750:1.

 

"Dynamic" Picture Mode:
The blue-tinted "Dynamic" picture mode makes no improvement to the ANSI contrast, but significantly increases the dynamic contrast adjustment for small bright spots. A small, one-percent white area on a black background then shines more than twice as brightly as in the "Cinema" mode, at around 300 candelas per square meter (cd/m2); the in-picture contrast increases to 7,700:1.

The "Dynamic" mode gets a bit smart with fully black images: The plasma display turns off completely, which would result in an almost infinite on/off contrast in a dark room. In practice, of course, the display turns back on as soon as even minimal video content is present. We know of no longer, fully black scene than the beginning of Stanley Kubrick's masterpiece "2001: A Space Odyssey", which displays a black picture for three minutes. Here, in the "Dynamic" mode, the Panasonic would switch off for the duration of the scene.

In the home-theater, however, the "Dynamic" mode is really more of a curse than a cure. With a full-screen white image, the mode actually results in a reduced brightness, since the display is optimized for the correct 6,500-Kelvin color temperature, which it displays in the "Cinema" mode. At 63 cd/m2, "Dynamic" is darker than the 75 cd/m2 that the "Cinema" mode produces when displaying a white image.

Like most plasmas, the Panasonic cannot compete with LCDs in very bright rooms - at up to more than 300 cd/m2, some LCDs can produce images four times brighter than the Panasonic! And despite the screen's contrast-increasing filter layer, the Panasonic reacts much more sensitively than many modern LCDs to external light sources; in a sunny living room, the pictures therefore look rather flat. The "Eco Mode" brings some relief, using a light sensor to adjust the gamma curve to suit the bright environment, at least saving the pictures from drowning altogether.

 

ANSI Contrast:

 

 

This test picture helps us determine the so-called ANSI contrast. The pattern gives a good indication of how strongly white areas of the picture brighten up neighboring black areas. A higher contrast here means movie scenes containing both bright light and shadows will look more contrast-rich. With an ANSI contrast of around 400:1, the Panasonic TX-P 42 GW 10 achieves a truly impressive value. But the best LCD competitors have now managed to catch up in this area.

 

Black Level Test:

 

 

The black test pattern shows how much so-called residual illumination the TV produces when trying to display pure black; technicians refers to this value as the "black level". Ideally, a black picture should appear perfectly black, but almost all TVs allow a small amount of light to leak through.

Several factors affect the way the viewer perceives this residual illumination: for example, how strongly the ambient illumination brightens up the TV screen (only slightly for LCDs, but rather strongly for plasmas), how high the TV's contrast ratio is, how light it is in the room, and how strongly the intensity of the residual illumination depends on the picture content.

In a rigorously darkened living room, the Panasonic TX-P 42 GW 10's "Cinema" mode delivers an extremely deep black of just 0.02 cd/m2. No color deviation is visible with the naked eye at such a dark value, although our Minolta CS-2000 measuring device did detect a minimal blue tint. Other than this 30,000-Euro Minolta, very few devices are even capable of carrying out accurate measurements at such low brightness levels.

Nevertheless, on the Panasonic, you can remove this blue tint using the "Advanced Settings" in the second picture menu. Already in the factory setup, the color temperature of a white image measures precisely 6,500 Kelvin - perfect!

In the "Cinema" mode, the Panasonic displays the classic "2001: A Space Odyssey" with a backdrop so pitch-black and stars so glistening that it really feels as if you're staring up into the infinite depths of a clear night sky. Current LCD TVs rarely achieve such grandiose contrast. Only Pioneer's KRP-500 delivers scenes like this with more contrast and plasticity.

 

Viewing Angle:

 

This diagram shows how picture quality varies with viewing angle. Ideally, we would see a circle or semicircle. The more club-shaped the diagram looks, the more strongly the picture quality depends on the viewing angle. Most plasma TVs are significantly better than LCDs in this respect.

The same goes for the Panasonic TX-P 42 GW 10, whose contrast and brightness hardly reduce when viewed at an angle of 60 degrees from the center. Colors, too, remain practically identical, as does the overall picture quality. To avoid geometric distortions, however, you should still point the TV toward the audience; in addition, make sure no windows other light sources are shining onto the high-gloss display.

 

Video Processing of Standard Signals:
With the Panasonic TX-P 42 GW 10, vice and virtue occupy the same airspace. On the one hand, the TV impresses with a switchable overscan setting, even for standard video, meaning it crops the picture less and produces a visibly better scaled picture than many other TVs. On the other hand, while the de-interlacer works well for TV material, it stumbles with movies - moving images flicker.

This is a real shame, since the sharpness and scaling are excellent via Scart RGB. Even the finest vertical structures in a test pattern appear with strong contrast; only the finest burst (6.75 MHz) of the horizontal test pattern exhibits slight colored artifacts. Resolution of color details is also impressive.

 

 

YUV images are a tad rougher on the Panasonic TX-P 42 GW 10, often showing edge-ringing effects. The S-Video input produces even stronger edge-ringing, requiring you to reduce the picture sharpness. With basic composite video signals the color resolution is poor, simply as a result of the technology's limitations, but the black-and-white resolution reaches top values without producing nasty fringing. The Panasonic TX-P 42 GW 10 therefore displays treasured home videos recorded on older camcorders in the best possible picture quality.

 

 

A great feature for picture-tweakers: You can switch off overscan even for standard sources, producing an almost cropping-free picture with finer detail resolution. The Panasonic makes this function available even for TV reception via all of the digital tuners, but not for analog cable broadcasts in 4:3 or letterbox format.

 

Video Processing of HDTV Signals:

 

With test images such as a stepped grayscale pattern, it becomes clear how uniform the Panasonic TX-P 42 GW 10 keeps the color temperature across all brightness levels. Blacker-than-black and whiter-than-white regions also display correctly. Apart from a slight flicker, the TV also displays the "Pixel Phase" test pattern accurately and with almost no color tint. Consequently, in the Batman adventure "The Dark Knight", the Panasonic chisels skyscraper façades onto its screen with glacial clarity, revealing the epic quality of the IMAX cameras used to record these shots above the Chicago skyline.

With this colored test pattern, the Panasonic TX-P 42 GW 10 delivers correctly decoded primary and secondary colors.

 

 

1080i de-interlacing: In an HQV test with movies in 1080/60i format, the Panasonic shows some comb-effects on the sides of objects. TV material appears perfectly in fast sideways-movements: The license plates of cars moving quickly through the picture, for example, show no comb-effects. A sequence with slow vertical motion, however, shows some slight flicker, which is visible in a woman's eyelashes in a test pattern where the camera moves slowly past her face.

The Panasonic TX-P 42 GW 10 displays movies without flicker if they arrive in 1080/60i format. At the beginning of the forth chapter of the Bond movie "Casino Royale", however, the decorative strips on the sea-plane still quiver slightly, an effect that only disappears fully when you switch to a progressive input signal (1080/60p or 1080/24p).

Here, the TV maintains the original frame rate, displaying the movie either with a slight 3:2-judder at 60 Hertz or with the original "movie look", using 24 motion phases per second. Panasonic's "Intelligent Frame Creation" motion-enhancement system has no effect here; it only generates intermediate frames for TV material at 50 or 60 Hertz.

 

Tuner Picture:

 

Analog Cable:
The analog TV tuner comes as a pleasant surprise - you rarely see such a crisp, noiseless picture, free from ground problems or Moiré effects. Broadcasts in 4:3-format are particularly impressive. We saw no MPEG block-artifacts in a football game on Eurosport, and the grass stayed clear even during camera pans. Unlike with some LCD TVs, motion looks very fluid, especially with "Intelligent Frame Creation" switched on.

 

DVB-C:
Digital cable TV also impresses with crisp pictures and excellent detail-differentiation. The colors look more saturated; especially red tones even occasionally look a little over-exaggerated. TV programs in 16:9-format and studio images reach DVD quality, since with overscan switched off the TV is able to display the image in maximum sharpness. The TV's outstanding motion clarity and enormous contrast occasionally lend even standard TV pictures an astonishing impression of depth.

 

DVB-T:
Digital terrestrial TV delivers similar quality to DVB-C, so long as the broadcast's bit rate allows it. Here, it's the quality of the broadcast material that limits your enjoyment, since during camera pans across a football field, for example, previously clear structures begin to blur, and unattractive MPEG block-artifacts billow in the dark background.

 

 

DVB-S:
With satellite TV, the Panasonic taps into the widest variety of channels and best transmission quality. If you have the option to install a dish, we highly recommend that you do so, especially since the built-in satellite tuner displays both SDTV and HDTV signals in excellent picture quality.

In very rare cases with HDTV broadcasts, there's a visible flicker on moving edges, but we didn't find this irritating from normal viewing distances. In one case, with a 720p-format documentary, the flicker came from the broadcaster - the Panasonic was not to blame.

An HDTV recording showing classic airplanes thundering across a snow-bleached, alpine landscape appeared gratifyingly crisp. Material broadcast in 1080i format fascinates with filament-fine, crisp details. Here it becomes clear that a 42-inch screen is almost too small for such picture quality, tempting the viewer to move closer to take in the breathtaking detail. Overall: The quality of all four integrated tuners is outstanding, and forms one of the strongest selling points of the Panasonic TX-P 42 GW 10.

The all-round user-friendliness during TV viewing is another of the Panasonic's strengths. Once the channels are programmed in, all reception types bless the user with convenient channel lists and excellent menu navigation.

 

Picture Uniformity and Digital Picture-Errors:
Plasma TVs such as the Panasonic TX-P 42 GW 10 display motion crisply from the word ‘go', but also show some slight artifacts. With a static test pattern showing various steps of gray, some bars flicker slightly, unlike with LCD TVs, and tend to look a little grainy - this effect is stronger with PAL video at 50 Hertz (Hz) than with NTSC video at 60 Hz. Even though the display runs at 100 and 120 Hz respectively, a few shades of gray still flicker in brighter areas of test patterns, or show some noise (dithering). With TV pictures, both effects become negligible, since the eye hardly has time to notice these areas in moving images.

What the Panasonic does do, even in real pictures, however, is to render so-called false edges in the picture, known as "False Contouring". You can see this in faces, for example, which take on a stepping effect during fast movements, losing some fine detail in comparison to static images. This is not, we hasten to add, a serious weakness. Among plasma TVs, only Pioneer's KRP-500 produces finer color gradients.

Otherwise, Panasonic's plasma technology offers some advantages, especially for moving pictures, thanks to its first-time use of "Intelligent Frame Interpolation". Instead of settling for basic playback of 50-Hz pictures, it generates additional motion phases, resulting in a picture with 100 frames per second (or 120 for NTSC). Most LCDs tend to blur moving edges more strongly - this is known as "motion blur". Unlike many of its competitors, Panasonic applies its image-enhancement technology only to TV material, and not to movies, which are based on 24 frames per second.

 

Intelligent Frame Creation:
This TV improves yet further on plasma technology's (already excellent) motion clarity, as we were able to prove with tricky DVD test patterns. On a swinging pendulum, the double edges that are initially still visible on the arrow head become finer, and the image appears sharper. Texts moving sideways through the picture are significantly clearer than with classical 100-Hz playback.

Slight comb-like artifacts are visible in SDTV test patterns, whereas the "Intelligent Frame Creation" technology processes HDTV material at 50 or 60 frames per second with almost no artifacts. The better and crisper the input signals, the more accurately the TV can interpolate intermediate pictures.

Even current LCD TVs such as the LG 42 LH 7000, with "TruMotion 100 Hz" technology, fail to rival the Panasonic in terms of motion clarity; fast-moving structures still blur more strongly. Only Sony's Z series, which uses "200-Hz Motionflow" technology, can produce results as impressive as those of the Panasonic.