Samsung LN40B610

Color Temperature (8.05)

When a HDTV shows white on the screen, the white has a particular color, a property that's measured as something called color temperature. As part of out calibration procedure, we set this color temperature to as close to 6500k as possible (for this display, that was the Warm3 setting, which was about 5500k). But many displays have problems being consistent with whites; as the whites turn to grey and black, the color temperature can shift and the whites get a color cast. That's what we test for here: we look at how consistent the whites are over the range of intensities from the brightest white to nearly black. The LN40B610 did reasonably well here: we saw some shifts in the color temperature, but these remained minor until we got into the very dark grays, where they did jump around a fair bit. However, most of the shifts are minor; on the graph below, anything within the green boundaries won't be noticed by most people.

Color Temperature

RGB Curves (8.03)

HDTVs create all of the colors on the screen by mixing red green and blue. So, it is important that a good display be capable of representing all of the different levels of these colors accurately. That's what we test here; how well the display can represent subtle changes in the signals it receives on the screen. If this response curve is bumpy, the display won't be able to show subtle color changes. We found that the LN40B610 had pretty smooth response curves, with only a few minor bumps and glitches. However, we did see some problems with peaking, where the curve flattens out at the top. This indicates that, although the incoming signal hasn't reached its maximum, the display has; it can't make the colors any brighter. What this means is that some highlight details in that color (such as a blue sky or a bright red uniform) might be lost, because the display can't show the subtle details that are present in the signal.

RGB Curves

To show what this measn in practice, we create these color strips that show how a color gradient would look on the display. One thing to consider; the display that you are reading this on may have its own problems, so if the ideal response (the top one) doesn't look smooth, your screen has a poor response curve.

Red Response Comparisons
Ideal Response
Samsung LN40B610
Sharp LC-40E67UN
Sony KDL-40S5100
Samsung LN40B650

Green Response Comparisons
Ideal Response
Samsung LN40B610
Sharp LC-40E67UN
Sony KDL-40S5100
Samsung LN40B650

Blue Response Comparisons
Ideal Response
Samsung LN40B610
Sharp LC-40E67UN
Sony KDL-40S5100
Samsung LN40B650

Color Gamut (4.15)

The range of colors that a display can show is called the color gamut. The range of colors that a HDTV signal should contain is defined in a standard called Rec.709, and on a good display, the two should be almost the same. We found that there were some issues here with the LN40B610; although the red and green limits of the gamut were almost spot on, the blue was significantly off. What this means is that while greens and reds will look the way that the director intended, blues will look overly saturated.

Color Gamut

For those who like to know the specific details of our tests, the color coordinates of our results and the Rec.709 specification are below.

Other Models in the LNXX610 Series
This is a review of the LN40B610, specifically. The other TVs in this series should be broadly similar in terms of performance and usability. For details about any differences, click on the image to jump to the Series Comparison page.
LN46B610 46'	LN52B610 52'