Screening Your Room: Stewart Filmscreen StudioTek 100 and StudioTek 130 G3 Page 3

I kept the projector settings the same for all of the measurements, with one exception. I calibrated the gray scale separately for each screen. First, I measured the StudioTek 100’s gray scale, keeping the calibration settings for the StudioTek 130 G3 in place (the 130 was first up to the plate for testing). The differences were very small—and inconsequential to the eye. But I still tweaked the settings for the StudioTek 100.

I ended up with 14 different color-tracking charts. Rather than risk your eyes glazing over, I’ll present only three for each screen, all of them taken on the left-right center line of the screen. Figures 3 and 4 show the calibrated center measurements for the StudioTek 130 G3 and the StudioTek 100. They are respectable but not perfect. As I mentioned above, we can’t attribute that solely to the screens. They’re not absolutely identical, but they’re certainly very close to it—as close as I could come in calibrating the projector separately for each screen.

What happens when we move halfway to the left edge of the screen? Check out Figures 5 and 6. Take your pick. Your guess is as good as mine as to which is better. In any case, you probably won’t see any color differences between the two screens in this area, even in a side-by-side comparison.

Moving to the far left side of the screen, Figures 7 and 8 indicate how difficult it is to find a projector/screen combination with perfect colorimetry across the entire image. If it could be done at all, it would probably be prohibitively expensive. The eye is very forgiving of small errors at the edges of the picture. If I had to make a call as to which result is better, it would be the StudioTek 130 G3 by a hair. But minor measurement anomalies could easily account for the small differences, and I can’t imagine them being visible on normal program material.


In fact, the readings I took in other areas of the screen but didn’t show here further indicate that it’s a toss-up as to which screen has better colorimetry. I wouldn’t even attempt to call a winner in this comparison. I’ll just say that most users, given a suitable viewing environment, won’t experience color issues from either the StudioTek 130 G3 or the StudioTek 100.

Next, I looked at how the luminance from each screen varies from the on-axis output as I moved 45 degrees off center. In this case, the projector isn’t really an issue. I took all four measurements at the center of each screen—two for each screen at full brightness (100 IRE), one on axis and the other at 45 degrees. I used a Minolta LS-100 light meter. On the StudioTek 130 G3, the center reading was 17.8 foot-lamberts. This dropped to 12.5 ft-L at 45 degrees. In other words, the brightness at that off-axis angle is 70 percent of what you’ll see when you sit directly in front of the screen. That result isn’t far off from Stewart’s published curve. In fact, it’s slightly better. (Figure 2 indicates that the brightness will reach the 70-percent level at 40 degrees.)

On the other hand, the result for the StudioTek 100 was surprising. I measured 15.6 ft-L on axis and 13.4 ft-L at 45 degrees. That’s a luminance retention of 85.9 percent at that angle. While this is significantly more than the StudioTek 130 G3’s 70 percent, it isn’t up to the claimed retention of about 97 percent based on analysis of Stewart’s own published Luminance versus Angle chart. (It’s not shown here, but it indicates virtually no loss, even at a 70-degree angle.)

Nevertheless, the StudioTek 100, measured at the center of the screen, produces only 87.6 percent of the center luminance of the StudioTek 130 G3 (15.6 ft-L versus 17.8 ft-L). But it actually produces higher brightness than the StudioTek 130 G3 (13.4 ft-L versus 12.5 ft-L) at a 45-degree angle. I also took brightness readings at different areas of the screen with the light meter returned to an on-axis location behind the projector. This was similar in setup to the colorimetry measurements, with the fixed-position meter aimed at different points on the screen (although we’re measuring brightness here, not color). The values of these brightness measurements include the characteristics of both the projector and the screen. Nevertheless, you can compare the readings at each point. Apart from its advantage in center brightness (measured at about 2.2 ft-L), the StudioTek 130 G3 had a brightness advantage greater than 0.5 ft-L at only one point (about 1 ft-L, halfway from midscreen to the top). It was actually dimmer in the corner, by almost 1.5 ft-L.

In short, like all screens with gain, the StudioTek 130 G3 has a hot spot in the center. It’s a very small one, and it isn’t visually obtrusive. But it is measurable. The StudioTek 100 has no measurable hot spot at all. While the StudioTek 130 G3 is brighter, that advantage is only significant at the center of the screen.

The StudioTek 130 G3 is a superb screen, and it’s likely to work well for most viewers, as it has for me. (I use an earlier-generation model, circa 2000.) But the StudioTek 100 proved to be even more impressive. After the formal tests, I zoomed out the Epson to the StudioTek 100’s full width and watched favorite scenes from the 2.35:1 Pirates of the Caribbean: The Curse of the Black Pearl. Even without an anamorphic lens (a common fixture with 2.35:1 projection), no one would guess that they were watching a $3,000 projector. The screen did its job and did it exceptionally well. The image consistency blew me away, and I hardly missed the reduced brightness, even with a 100-inch-wide screen. If you have the strict environmental control that this screen requires, plus a reasonably bright projector, it won’t let you down.