Sony QUALIA 004 SXRD video projector Calibration & Tech Test
Tech: The SXRD technology appears to be similar to that of Liquid Crystal on Silicon (LCoS) displays such as those marketed by JVC (D-ILA), as well as a few rear-projection models from Toshiba (apparently discontinued) and Mitsubishi. Sony claims some proprietary refinements and, most important, a high enough yield to make the products practical, particularly in the quantities needed to eventually bring costs down. It's this issue that has discouraged more than a few other manufacturers from entering the LCoS market.
Ordinary LCD panels are transmissive; the light from the lamp or other light source must pass through them on the way to the viewer. SXRD, like LCoS, is reflective (see Fig.1). That is, the light passes through a liquid-crystal layer, which controls the light from each pixel, then is reflected back out. This has one significant advantage. The circuits needed to drive each pixel can be located in a silicon backplane behind the panel (which does not need to be fully transparent) rather than in the gaps between pixels (where they must be placed in transmissive LCD displays).
This means that, in a reflective LCD, the space between the pixels, called the pixel pitch, can be far smaller. In the QUALIA's three SXRD devices (one for each of the primary colors), this pitch is 9µm, or 12% of the thickness of a human hair. Thus, the 2,073,600 pixels of the 1920 x1080 device can fit on a chip measuring just 0.78 inch diagonally (Fig.2). This both dramatically increases the amount of light that can reach the viewer and reduces the visibility of the pixel structure—the so-called "screen door" effect.
Sony claims other important characteristics for the SXRD panels. A thin (2µm) liquid-crystal layer results in a response time (rise and fall) specified as only five milliseconds, with none of the image lag that afflicts most LCD devices. A contrast ratio of 3000:1 is claimed for the SXRD panel itself, somewhat less for the overall projector. The liquid-crystal layer is said to be thermally stable for a long operating life. The pure xenon lamp—the type used in commercial movie theaters—has a more even color spectrum than the UHP lamps used in most digital home-theater projectors. The lamp is surrounded by an elaborate heatsink ; as a result, the fan can be very quiet, particularly in the Low lamp mode. There's also a high-altitude fan setting. I'm sure Sony must have forgotten something here, but I haven't yet figured out what that might be.
Test: The QUALIA 004 fully resolved all the test patterns available to me, both standard- and high-definition. In fact, most of the problems I saw could be traced to the source. Black-level retention was good, and luminance ramps showed no obvious banding. Overscan measured essentially zero with any DVI or component 1080i input, but from 3% to as high as 5% (depending on the source component) with either a DVI or component input at 480i, 480p, or 720p. We'd like to see an overscan of under 2.5% under all conditions (or, even better, a user option of under 1%). But the QUALIA's somewhat excessive (in our opinion) overscan with most sources is quite common in the industry.
The Before color-temperature readings, with the QUALIA set to its Low mode, as received, is shown in the accompanying figure. All measurements were made on my Stewart FireHawk screen (16:9, 80 inches wide—the 96-inch-wide screen measurements presented here were made with the projector lens zoomed out to simulate a screen width of 96 inches). This set of readings was taken with the Color Space set at Wide, before our measurements of the red, green, and blue color points showed them to be more accurate in the Normal setting (see "Delivery Day +4" in the main text of the review). But measurements also showed that switching from Normal to Wide increases the color temperature by about 200 kelvins. Therefore, the curve shown would read about 200K lower in Normal. The changes in the Wide Color Space setting affect the position of the primary colors with little change in the resulting gray scale; i.e., little change in the color of gray.
The After calibration curve shown was taken with a DVI input from the V, Inc. Bravo D1 player set to 1080i and the QUALIA's Color Space control set to Normal. The actual points are very close to the desired D65 across the board. Apart from the slight color shift across the screen noted in the review with specific test patterns (hard to spot with typical program material) and a subtle green shift visible primarily on black-and-white material when the projector was not precisely calibrated, the QUALIA's colorimetry is excellent. (Hint to fans of classic films: B&W movies often look best at 5600K. You might want to program this value into one of the color-temperature memories.)
Calibrators should know that, of the six color-temperature settings available on the QUALIA, Custom 1, 2, and 3 have sub-bias and sub-gain settings in the service menus that operate in tandem with the user settings. Even if you set the same numbers in the three Custom user options, the result won't be identical for all three of them unless the Custom service settings are identical—and they generally will not be. But the user Low, Middle, and High settings have only one group of settings each, which are located in the service menu.
I performed an additional calibration for high-definition sources. These aren't shown here, as they don't differ substantially from the results shown in the After curve. In fact, in experimenting with changes of screen, screen size, source (HD, component SD, DVI SD), and control settings (Brightness, Contrast, Color), the color temperatures didn't shift beyond the acceptable—usually less than 200K across all but the very top and bottom of the brightness range.
All of my readings were made with the iris on its smallest opening, 2, and the lamp on Low. But if you plan to use brighter settings of the iris and lamp, I recommend that the installer provide separate calibrations for all combinations of lamp and iris settings and sources likely to be used, particularly for the brighter modes, which would be more appropriate for watching in a room with significant ambient light. Fortunately, that's possible with this projector. On my 80-inch FireHawk screen, with the QUALIA's lamp set to High and its iris Open, the Sony produced a searingly bright 41.4 footlamberts peak white! Still, you'll always get the best image with tightly controlled room lighting. And with the QUALIA's replacement lamps costing $3000 each, I sure wouldn't be using this projector to watch the nightly news.—TJN