Sony KDL-40R510C LED TV Review
Sony's entry-level TV is perfect for cinephiles on a budget
The Sony KDL-40R510C is an excellent performer with few flaws, especially for the asking price. In Sony's Cinema mode (or "scene"), the TV proved to be very accurate and well-engineered, producing ample contrast results, spot-on color/grayscale matching, and standard gamma performance. Most TVs in this price range can accommodate such performance, but you'd have to pay for a professional calibration—a process that can cost almost as much as the TVs themselves.
Coincidentally, calibration—or lack thereof—is one of this Sony's only drawbacks. In the Cinema picture mode, you simply can't access any of the controls. Even simple settings like backlight, color, and contrast are barred. In fact, the entire "picture settings" menu is grayed out in Cinema mode, meaning you're stuck with the defaults. Fortunately, the default settings are very accurate.
Contrast (and black level) are major keystones of video quality, and the R510C is a heavy hitter in that regard. I measured a black level of 0.018 cd/m2 alongside a reference white of 130.50 cd/m2, giving the R510C an ANSI checkerboard contrast ratio of 7250:1, which is absolutely incredible in this price range. Further measurements saw some shift in black level depending on screen APL, with occasional measurements as low as 0.015 cd/m2 (in Cinema mode).
Our viewing angle test measures the horizontal viewing flexibility of a TV's screen. We measure full-field black/white screens from head on (0°) and move in 10° increments, increasing the angle of view until the TV's contrast ratio drops below 50% of its original head-on value (from full-field, not from ANSI). The KDL-40R510C performed with average results here: I measured a total viewing angle of 36°, or ±18° from the center to either side of the screen. This compares normally with other LED (LCD) TVs in this price and size range.
A TV's color accuracy is not subjective: Exact coordinates (usually measured in x, y, and Y) of primary and secondary colors are compared to the international standards for a TV's given color target. The R510C is an HD (rather than a UHD) TV, so it aims for the BT.709 color space coordinates (as well as the standard D65 white point). The R510C performed very well here, boasting accurate primaries (red, green, and blue) and mostly accurate secondaries (cyan, magenta, and yellow). The white/gray point is supremely on-point, too, which is very rare in this price range.
Grayscale & RGB Balance
TVs produce grayscale elements—lighter blacks, dark, mid-, and light grays, and highlight elements—using a combination of their primary colors. According to standards, even emphasis of primary colors should result in grayscale elements that correlate to a color temperature of 6500K, with exact coordinates of x = 0.313, y = 0.329. When primary colors aren't emphasized evenly, perceptible errors in the grayscale arise, with collective error measured in deltaE.
A grayscale deltaE of 3 or less is ideal. By default, the R510C tested with a grayscale deltaE of 4.59, which is a little higher than ideal, but is still a good result for an out-of-the-box, uncalibrated measurement.
If we take a closer look at the primary color emphasis behind the R510C's grayscale production, we can see where some of the error stems from. The red, green, and blue lines will ideally each sit at 100% emphasis from 10 through 100 IRE—when one or two colors gets more or less emphasis, it creates visible error and tinting within grayscale elements. This isn't an extreme result at all, though, as all errors are contained within about 3% emphasis error (above or below 100%).
In displays, gamma is a measurement of how luminance is allocated across the visible spectrum from the darkest black to the brightest (reference) white. While the ITU recently standardized HDTV gamma in a document called BT.1886, many TVs still adhere to power-law based gamma curves like 2.2, 2.3, or 2.4.
The R510C tested with a mostly flat gamma sum of 2.38, which is quite close to the 2.4 standard, which is ideal for very dim or totally dark rooms. This result really cements the R510C's status as a dark room/theater room TV, but means you probably don't want to use the Cinema picture mode if you're watching in a room with lots of competing ambient light.
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