Panasonic TX-L47ET60B 3D LED TV Review

2D Calibration

Note: Our Panasonic TX-L47ET60B review sample was calibrated using Calman Professional, the industry-leading video calibration software.

Greyscale

Pre-calibration RGB Tracking
Pre-calibration Delta errors
Pre-calibration RGB tracking and delta errors (dEs)

The Panasonic TXL47ET60 produced grey shades with excellent accuracy, with only a very minor red tint being visible in the default “True Cinema” mode. In fact, more problematic is the number of steps needed to shut off unnecessary video processing features – we still had to dial [Sharpness] down to 0 to avoid ringing around lines in the image being drawn by the television (shouldn’t “0″ be the default setting for a mode called “True Cinema” anyway?)

As an edge-lit LED LCD TV, we had a purpley-blue tint hanging around in the shadows, which you can see at the very left of the chart. This is a characteristic of the LEDs themselves, and on an affected LED TV, is unavoidable, because in dark areas of the image, the panel is showing a total absence of coloured pixel data. While a calibrator can pump more red into, say, 10% grey to offset the blue tint, you can’t change the colour of black via software processing tricks (not without turning the blacks grey, anyway). However, the “blue shadows” effect is less than last year’s ET50, which makes us wonder if Panasonic have pre-programmed some compensation in for this.

Post-calibration RGB Tracking
Post-calibration Delta errors
Post-calibration RGB tracking and dEs in [True Cinema] mode

We were able to get a very good result from the TX-L47ET60 during calibration. IPS LCD panels typically show very linear greyscale tracking, and, with the usual LED LCD proviso of “blue in the shadows” notwithstanding, we found the same was true here. We only had to use the basic two-point Greyscale adjustment to dial out the slight red tint across the entire range of shades. We did use the 10-point control (which is in a menu called [More detailed adjustment]) to add more red at the 10% and 20% positions to correct some more of the blue glow coming from the light sources.

Long-time readers might be wondering why we didn’t correct the blue tint at the 90% and 100% levels. That is a conscious decision on our part. In order to fix this, we would have to have pulled back on the [Contrast] control by a significant amount (on the Viera TX-L47ET60B, [Contrast] acts a control for digital white level, unlike older Panasonic LCDs). That would dim the picture, unless we turned up the [Backlight] setting in order to achieve the same level of brightness from the screen – which in turn, would cause blacks to get greyer (and for the aforementioned “LED blue shadows” to creep higher and higher up the dynamic range). Given that IPS LCD panels don’t have great black-level performance, we wanted to use as much of the dynamic range of the LCD panel as possible – even if it meant a barely visible excess of blue in the shadows.

These are the kinds of trade-off decisions that a good calibrator will discuss with the customer. Put another way, the blue tint we left in the highlights is the lesser of a few evils.

Gamma

Pre-calibrated Gamma tracking in [True Cinema] mode Post-calibrated Gamma tracking in [True Cinema] mode
Pre-calibration gamma tracking (avg 1.9) Post-calibration gamma tracking (avg 2.29)

Pre-calibrated gamma in the “True Cinema” mode averaged at 1.9. Light output from the screen became more and more exaggerated the brighter the image got. When we calibrated the 47ET60 for use in a slightly darker environment, and therefore aimed to hit the recommended dark-room gamma of 2.4, we were left with a slight excess brightening in the 60-90% range, although we didn’t find this too visible. (In case you’re wondering, the 10-point Gamma control can’t defeat it either – nor can the Game Mode or the 1080p Pixel Direct mode, which we were using anyway).

What’s interesting here is that the Panasonic TX-L47ET60B does have a setting called [Adaptive Gamma Control], which is greyed out and is reported as being set to “0″ when the [Adaptive Backlight Control] is set to Off. However, there is a bug where the control can actually still be running, even when the menu screen gives the appearance of it being non-operational. So, even if you don’t plan on using the Adaptive Backlight mode, turn it on (on either of its settings), enter [Advanced Settings], and double-check that Adaptive Gamma Control is selectable, and dial it down to 0. Then, you can turn the [Adaptive Backlight Control] off and get static gamma behaviour without any darkening or brightening of scenes at the video processor level.

Colour

As usual for Panasonic, colour accuracy is absolutely excellent, provided you avoid the “gotcha” we mentioned above where the TV can tell you lies about the adaptive gamma processing being off. Only a very minor hue error with magenta, cyan and green were uncorrectable, and luminance levels for all the colours were absolutely within non-troubling levels.

We’re showing the post-calibration result here and omitting the pre-calibrated state just to save space, since there was so little difference. (Tip for other calibrators: avoid the temptation to perfect the hue and saturation of red when measured with full saturation: it severely distorts red at 75% and below).

Colour saturation tracking
Post-calibration colour saturation tracking
Post-calibration Gamut Luminance levels in [True Cinema] mode
Post-calibration gamut luminance (coloured bars = targets; black bars = measured values)

3D Calibration

3D Mode Greyscale

3D Pre-calibration RGB Tracking
3D Pre-calibration Delta errors
3D Pre-calibration RGB tracking and delta errors (dEs)

We taped a pair of the supplied Panasonic polarized 3D glasses (which look very cool, by the way) to the front of our Klein K-10 colorimeter, engaged the 3D display mode with “flat 3D” greyscale test patterns, selected the 3D True Cinema mode, and measured the above grey shades. As you can see, the performance here is not on the same level as in 2D, with the eyewear blocking blue from reaching the viewer’s eyes the brighter the image gets. Each pair of glasses is slightly different, but we still think Panasonic could do a little more to get some idea of what an “average” pair of passive 3D glasses looks like, and program some basic compensation into the 3DTV – which is exactly what we’re about to do next:

3D Post-calibration RGB Tracking
3D Post-calibration Delta errors
3D Post-calibration RGB tracking and dEs in [True Cinema] mode

After manipulating the [White Balance] controls with the readings from our colorimeter, we were left with fantastically accurate grey shades in the third dimension. The beige-ish tint from before calibration was gone, with absolutely no severe tints left in the image. We’ll find out how that looks with actual extra-dimensional content, rather than test patterns, in just a second.

3D Mode Colour

3D Post-calibration CIE chart in [True Cinema] mode
3D Post-calibration CIE chart with reference to HD Rec.709
3D Post-calibration Luminance levels in [True Cinema] mode
3D Post-calibration colour luminance (coloured bars = targets; black bars = measured values)

Benchmark Test Results

Dead pixels None
Screen uniformity Subtle purple darkening near edges, mild “dirty screen” effect; but actually very good by edge-lit LED LCD standards
Overscanning on HDMI 0% with [16:9 Overscan] set to “Off
Blacker than black Passed
Calibrated black level (black screen) N/A, edge LEDs dim to near-black, measurement void
Calibrated black level (ANSI checkerboard) 0.118 cd/m2
Black level retention Auto-dimming with full black screen, controllable otherwise with [Adaptive Backlight Control]
Primary chromaticity Excellent
Scaling Excellent
Video mode deinterlacing Effective jaggies reduction
Film mode deinterlacing Passed 2-2 PAL and 3-2 NTSC tests ([Film Cadence Mode] on)
Viewing angle Very Good for an LED LCD TV; colours remain largely saturated but blacks brighten
Motion resolution Around 1080 lines, [Intelligent Frame Creation] “Max” and [1080p Pixel Direct] disabled – see notes
Digital noise reduction Defeatable (Excellent)
Sharpness Defeatable edge enhancement (Excellent)
Luma/Chroma bandwidth (2D Blu-ray) Full Luma, Full Chroma, in the [1080p Pixel Direct] mode
1080p/24 capability No judder in 2D or 3D
Input lag 34ms compared to CRT TV
Full 4:4:4 reproduction (PC) Yes, with [1080p Pixel Direct] on

Power Consumption

Default [Normal] mode (2D) 59 watts
Default [Normal] mode (3D) 67 watts
Calibrated [True Cinema] mode (2D) 43 watts
Calibrated [True Cinema] mode (3D) 60 watts
Standby 1 watt

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