Samsung’s latest HDTV flat panel offering, the 40” LN-T4081F, significantly raises the LCD performance bar, providing the highest LCD panel motion resolution ever measured, accurate color and the best black levels and dynamic rated contrast ratio (would you believe 500,000:1) of any flat panel.

The secret sauce? The 81 series are the first large screen LCDs that incorporate white LEDs (light emitting diodes) as a light source instead of fluorescent lamps (usually CCFL-Cold Cathode Fluorescent Lamps). The 81 series also features localized dimming (Samsung calls it “Smart Lighting”), providing another LCD first, which is the ability to turn the intensity of the light source either down or off in the areas where the image is dark or black.

The LN-T4081F ($2999; review sample is a pilot production unit) represents the top of Samsung’s LCD HDTV line (the series also includes 46”, 52” and 57” sizes). In addition to its unique back lighting system, the 81 series has other high-end Samsung features that include side firing speakers, a rear firing woofer, three HDMI inputs (one on the side), two component video inputs and a USB memory reader (for photos).

The LN-T4081F has a “pixel for pixel” aspect ratio to display all the image information that is contained within a high definition broadcast or high definition disc to appear on the screen. Samsung calls it “Just Scan”. Samsung also provides a Gamma adjustment (Gamma is the rate of transition from black to white) using presets. The “–3 “setting position was the most accurate setting.

As with some other recent Samsung LCD flat panels, this series features a shiny anti-reflective screen coating similar to ones found on many plasma panels. The shiny coating increases image contrast and produces “more vibrant colors,” according to Samsung’s website. Unfortunately, it also produces well-defined reflections of bright objects such as lamps located opposite the viewing position, though most people have the good sense to both keep such light sources away from viewing room locations likely to produce such reflections, and for daytime viewing, to cover windows with blinds and/or curtains.

I prefer the shiny, anti-reflective coating found on these new sets as well as on most plasmas and on some of the latest LCDs over dull anti-glare coatings and I am amazed that some LCD manufacturers continue to use “anti-glare” as a major selling feature to distinguish their sets from “anti-reflective” plasma sets.

The heart of the Samsung LN-T4081F is its 1080p (1920 x 1080 resolution) S-PVA LCD panel, the same one used in other top Samsung models as well as many of the larger panels in Sony’s XBR series (Sony and Samsung co-own a factory that produces these panels). The S-PVA LCD panel has the best angle of view and response of any LCD Samsung produces (there’s more on viewing angle later).

The local dimming feature incorporated in the 81 series models produces a black screen when there is no signal on the screen by completely shutting off all of the LEDs. When the content includes black areas in a portion of the image, the LEDs behind the dark area turn off. The TV’s local dimming circuit monitors the content and, zone by zone, constantly changes the LEDs’ intensity, depending on the content.

Samsung combines the local dimming feature with what it calls “Motion Plus,” a scanning technology that activates the horizontal rows of LEDs progressively from top to bottom to dramatically decrease motion blur in this 60Hz panel. With Motion Plus activated, the panel measured a record-setting (for LCD) 800 lines of horizontal measured resolution (using the “FPD Benchmark Software for Professional” 1080i Blu-ray Test Disc), which is 33% greater motion resolution than that of any other LCD panel tested to date including 120Hz models from Sharp and Sony. That ranks the LN-T4081F near the best set ever measured (900 lines, the soon to be reviewed Pioneer PDP-6010FD). With Motion Plus in the “off” position, resolution dropped to 550 lines, which is just short of the 600 lines of the best previously tested 60Hz LCD panels.

Sampling a variety of high motion content, including action movies like “Spiderman 3” and NFL football, confirmed the freedom excessive motion blur that’s been seen on every competing LCD panel sampled to date.

A series of objective tests confirms the LN-4081F’s ability to properly handle a 1080i HD signal, the type most commonly used for broadcast, satellite and cable HD programming. The Samsung displays full bandwidth of 1080i multiburst “single pixel on/ off” test pattern generated by a Sencore VP403 signal generator.
The Silicon Optix HD HQV test disc verified the LN-T4081F’s ability to both properly de-interlace 1080i signals to 1080p and to perfectly execute 3:2 pulldown conversion needed to maintain full resolution without added artifacts when viewing film based HD content used in a number of TV series and in movies.

Color temperature and the color point measurements indicate that gray scale was close to ideal using the “warm 2” setting. There are user controls for setting the gray scale (called “white balance”), but proper settings require sensitive and accurate test gear in the hands of a trained calibrator. I was able to quickly obtain an excellent result: a minor deviation from D6500K of +186K/-185K using the set’s “white balance” controls with readings from a Photo Research PR650 spectroradiometer.

Measuring the color accuracy against the HDTV 709 standard using the LN-T4081’s “auto” color mode, the xy coordinates of the three primary colors Red (R), Green (G) and Blue (B) were near-perfect, providing naturally green grass on football fields, accurate blue skies and crimson reds. For the “tweaks” reading this, the measurements (with the standard in parentheses) were R= x.647 (.640) y .322 (.330) G= x.299 (.300) y.603 (.600) and B =x.150 (.150) y .055 (.060).

Black levels were lower than I was able to accurately measure. With a blank screen, all LEDs are shut off, resulting in completely black levels. White writing against a black background, produced a considerably higher black level—visually higher than blacks on Pioneer’s Kuro Plasma displaying the same content, but it was still very dark and darker than I have ever seen on an LCD flat panel. In other words, the local dimming effectively and significantly decreased the level of black. The (off axis) pictures below show the effect of local dimming “on” and “off.” with the cameras sensitivity maxed out. The straight on shot illustrates the black level with normal viewing.

One other feature that is deserves mention is the LN-T4081F’s energy efficiency. Using a full frame white pattern at 20% (20IRE) the Samsung consumed an incredibly low 79 watts a level that is the lowest I have ever measured. This reading was made with the Motion Plus and Smart Lighting circuits activated and contrast set at 90.

While the color, black level and overall image was excellent, the LN-T4081’s performance fell short in a number of areas, including its handling of 480i signals. The Silicon Optix HQV DVD produced a score of 0 out of 10 for the “jaggezze” test, with straight diagonal lines producing unwanted artifacts seen as a saw tooth pattern at the top and bottom of the lines. The set also failed the 3:2 pulldown test when fed standard definition 480i signals. Fortunately, with the advent of upconverting external set-top boxes (cable, satellite, surround sound receivers, scalers) and DVD, HD DVD and Blu-ray players with good processing, an HDTVs ability to effectively upconvert 480i has become less important, though I would preferred that the 408i passed these tests.

Another shortcoming is the set’s tendency to occasionally cause fast moving objects to “ghost,” producing a second faint image next to the main one. This can be seen in the photos of the cars bellow. This artifact appeared whether or not the Motion Plus circuit was activated, which indicates that the problem may be with either the panel itself, or with another circuit, and not with the set’s motion blur reduction capabilities. With actual program material, the anomaly was present only occasionally and from a viewing position far closer than the maximum optimum distance of about 6 ½ feet for a display of this size.

The final shortcoming was with the set’s viewing angles. As one moves about 20 degrees off center, blacks appear lighter, whites darker and colors become less saturated. This effect is more pronounced than I have seen with Samsung’s S-PVA panels using conventional CCFL backlights. Perhaps the LEDs have lenses with their own optical properties? These “issues” were minor and far outweighed by all of the set’s positive picture attributes.

At HD Guru we are always on the lookout for better performing high definition displays, regardless of the technology. To date, to the dismay of manufacturers and some readers, LCD flat panels have lagged behind other HDTV technologies in their ability to produce the best high definition images, especially in motion resolution and black level.

The LN-T4081F sets new high LCD performance levels for contrast and motion. This is the first LCD to be awarded the top ♥♥♥♥ HD Guru rating.

If you are considering purchasing any LCD HDTV the HD Guru suggests judging its performance against that of one of these new Samsung 81 series panels. Based on the HDTV test results and many hours watching movies and television content, the Samsung LN-T4081 is the best LCD HDTV available today. If you can afford it, buy it.

Copyright ©2007 HD Gary Merson/HD Guru™. All rights reserved. The content and photos within may not be distributed electronically or copied mechanically without specific written permission.

LED Local Dimming “SmartLighting” Circuit On


SmartLighting Local LED Dimming Circuit On- Off Axis


Local LED Dimming Circuit Off- Viewed off-axis to highlight uniform level in dark area


Screen Close-up of Moving Car: Note Ghost Image on License Plate (Shutter Speed 1/200 second)