Panasonic Viera TC-L37D2

Color Temperature (9.59)

The Panasonic TC-L37D2 showed only very minor problems with color temperature consistency. As the chart below indicates, the color temperature wavers as it moves through the spectrum. Only rarely, however, does it stray into the limits of human perceptibility. You’ll probably never notice the errors. More on how we test color temperature.

Read Reviews of Comparison Products
Panasonic Viera TC-P42U2	Samsung LN40C630	Sharp Aquos LC-40LE700UN

RGB Curves (3.10)

The Panasonic TC-L37D2 scored exceptionally poorly in the RGB color curve tests. In fact, the results were so bad that we checked them again, re-evaluated our methods, and ran the tests yet again under and alternate picture mode.

As is the custom, we started the calibration process by putting the TV in Cinema mode. This setting (sometimes called Movie mode on other TVs) almost always allows for the most accurate color performance. It’s then only a matter of adjusting a few other settings to get the best overall performance. The results of the RGB test in Cinema mode are below. What you should be seeing here is a smooth, upward-reaching curve from left to right. For whatever reason, the green channel managed it, but the blue and red channels completely fell apart.

What’s unusual here is just how bad the performance is, and trying to hypothesize why it failed. There are several test screens that we, as editors, use to evaluate color performance by the eye before we run the hard tests that derive these charts. To the eye, we could tell that the blue channel and red channel were losing detail after a certain brightness (a value of around 240, for your technically-inclined readers). But the charts below indicate that the red and blue and having problems even in the mid-tones. We can only suspect that the TV must be performing some sort of heavy-handed dynamic contrast ratio or similar video processing, and that this feature cannot be turned off by a user.

RGB Curves (Cinema Mode)

After receiving the results above, we ran the tests again with the TV in Custom mode rather than Cinema mode. All we can say is ‘different, but not better.’ The red channel and blue channel simply can’t display properly above a certain brightness. More on how we test RGB curves.

The strips below are digital recreations, point for point, of the test results for the Panasonic TC-L37D2 and its three competitors. Note the strange color banding in the red channel compared to the ideal response and the other TVs.

Red Response Comparison
Ideal Response
Panasonic Viera TC-L37D2
Panasonic Viera TC-P42U2
Samsung LN40C630
Sharp Aquos LC-40LE700UN

Green Response Comparisons
Ideal Response
Panasonic Viera TC-L37D2
Panasonic Viera TC-P42U2
Samsung LN40C630
Sharp Aquos LC-40LE700UN

Blue Response Comparisons
Ideal Response
Panasonic Viera TC-L37D2
Panasonic Viera TC-P42U2
Samsung LN40C630
Sharp Aquos LC-40LE700UN

Color Gamut (5.44)

The Panasonic TC-L37D2 actually managed a decent color gamut, despite the disaster that is the RGB color curves. Let it be said that the color gamut test only measures four points, a red, a green, a blue, and a white point (the circles in the center of the triangle) and compares them the rec. 709 color standard. As you can see from the chart below, the color points matched up quite well, though the white point was a bit too blue. More on how we test peak color gamut.

The table below contains all the numeric details of the Panasonic Viera TC-L37D2’s color gamut performance, compared to the rec. 709 standards.

Rec. 709 versus Panasonic Viera TC-L37D2
	u' (rec.709/measured)	v' (rec.709/measured)	Error
Red	0.4507 / 0.4551	0.5229 / 0.523	0.004401136
Green	0.125 / 0.1278	0.5625 / 0.5638	0.00308707
Blue	0.1754 / 0.1798	0.1579 / 0.1503	0.008781799
D65 (White)	0.1978 / 0.1975	0.4683 / 0.4541	0.014203169

Other Models in the TC-LxxD2 Series
For more information on other models in this series, check our Series Comparison Page.
Panasonic TC-L42D2 42 in.