Samsung PN51D550 3D Plasma HDTV Review

Black Level

The Samsung PN51D550 managed a decent black level, but it's certainly not as good as the average plasma TV. In fact, the Sony EX720, an LCD TV, managed a better black level. The Samsung PN51D550 isn't terrible, but it's not great either. More on how we test black level.

Peak Brightness

While we didn't love the Samsung PN51D550's black level, the peak brightness was better than a lot of plasmas we've reviewed. It's not great. We want to see peak brightnesses over 200 cd/m 2 if you want to compete with the ambient light of a sunny room. More on how we test peak brightness.

Contrast

The Samsung PN51D550's contrast ratio was hurt by its less than stellar black level. With a measured contrast of 1942:1, it's pretty good, but not great. As you can see, both the Panasonic (a plasma) and the Sony (an LCD) had wider contrast ratios. More on how we test contrast.

Tunnel Contrast

Like many plasmas, the Samsung PN51D550 had a hard time maintaining a consistent black level. An all-black or mostly-black screen will have a much deeper black level than a small area of black surrounded by bright white. LCDs typically don't have this problem. More on how we test tunnel contrast.

White Falloff

The flip-side of the tunnel contrast test, white falloff measures the peak brightness consistency. Again, the Samsung PN51D550 had a hard time, as you can see in the chart below. More on how we test white falloff.

Uniformity

The Samsung PN51D550 has near-perfect uniformity, meaning you don't see any uneven illumination. More on how we test white falloff.

Greyscale Gamma

The greyscale gamma test measures how a TV transitions from black to white. Look at the chart below. First, we're looking for a smooth line. The Samsung PN51D550's line is not terrible smooth. There's that weird hook in the lower left, which represents the shadow details. It appears that the black level was brighter, then darker, then brighter again. After that, the response smooths out (with a few kinks). As it approaches the midtones to highlights, the curve becomes more horizontal, which indicates that you'll see fewer values in what should be a smooth gradient.

There's also the slope of the curve to consider. An ideal curve is between 2.1 and 2.2. The Samsung PN51D550 had a curve of 2.03, making it the rare TV that's shallower than ideal (most are steeper). More on how we test greyscale gamma.