Panasonic PT-AE1000U 1080p Video Projector Tests and Calibration

Tests and Calibration

All of the measurements, calibrations, and viewing tests in this review were performed with the dynamic iris On, unless otherwise noted.

Before calibration, none of the standard User color temperature settings or Picture Modes produced particularly accurate results. I worked from the Cinema1 mode, not because it necessarily produced the best color points, but because it appeared to be a good starting point for grayscale calibration. (The Color1 setting was similar, but both of them had color temperatures, out of the box, that averaged around 5700K.)

The Before plot shown in the chart was taken in Cinema1 with the Color Temperature control set to the -2 position. The post-calibration result is considerably better, with the white points within +/- 0.003 of the correct values from 30IRE to 95IRE.

The color points, out of the box in Cinema1, were comparable to those of most other digital displays we've tested. Most of them were a bit oversaturated, which is more common than not among digital displays.

That's when a lamp went on over my head. If Panasonic's Color Management system can be used to tweak the colors for such things as flesh tones in a real image (a dubious proposition, as noted in the review), then why not use it to tweak the primary and secondary colors? Simply use test patterns of the primaries and secondaries, measure them, and adjust each to be as close to the desired result as possible.

For a target I chose the standard ATSC (DTV, HDTV) color point coordinates. It proved to be a trickier operation than I had anticipated. You need precise measurement gear capable of taking a spot reading on the screen. Fortunately, our spot-reading Photo Research PR-650 spectrocolorimeter was handy.

The measurement spot must be centered in a small on-screen adjustment box. The three adjustable parameters are interactive but don't always operate in any predictable fashion, and have names—color, tint, and brightness—that tell you nothing about how to adjust them for this exercise. Moreover, the coordinates you arrive at by painstaking trial and error change when you exit the menu! I had to experiment with offset settings while in the menu, hoping that offset would shift me to the correct point when I exited. I spent literally hours going back and forth, but when I was finished most of the colors were measurably more accurate, with only cyan arguably a bit worse. We don't normally publish the measured color coordinates because their significance isn't always easy to interpret, but I'll make an exception here.

Red (x/y)
Out-of-box 0.662 0.336
ATSC standard 0.64 0.33
Calibrated 0.644 0.326

Green (x/y)
Out-of-box 0.287 0.665
ATSC standard 0.3 0.6
Calibrated 0.293 0.613

Blue (x/y)
Out-of-box 0.142 0.056
ATSC standard 0.15 0.06
Calibrated 0.147 0.059

Yellow (x/y)
Out-of-box 0.442 0.532
ATSC standard 0.419 0.505
Calibrated 0.418 0.498

Cyan (x/y)
Out-of-box 0.211 0.327
ATSC standard 0.225 0.329
Calibrated 0.212 0.307

Magenta (x/y)
Out-of-box 0.334 0.161
ATSC standard 0.321 0.154
Calibrated 0.316 0.151

But this is where it gets interesting. I saved the six calibrated color points (three primary, three secondary) in a User Profile. The on-screen menu then lets you shift from Normal (the factory color points) to the recalibrated result. The difference was shocking, but not in the way I expected. It was virtually impossible to see a change when I shifted back and forth on most program material, and even on test patterns.

Nevertheless, the post calibration color on the Panasonic (grayscale calibration and color point adjustment) is easily the equal of anything I've seen from any projector I've reviewed, regardless of price.

The Panasonic had good resolution on the multiburst test patterns from my AccuPel test pattern generator. The response on the highest bursts at all resolutions was visible, with one exception: There was no 37.1MHz response over component at 720p. In other high-definition bursts, however, the resolution lines at 37.1MHz were clearly visible, though dimmer than the 18.5KHz bursts. This indicates a rolloff in the response at the higher frequency.

One oddity: The 1080i, 37.1MHz burst had an orange (!) tint. I have, as yet, no explanation for this. The white field uniformity of the projector was good, and the convergence of the three LCD panels good also, though not perfect. The green and red were off by roughly a half pixel over much of the screen (including the center) and slightly more on the right. There was zero overscan at 1080i and 720p, and a maximum of 3% in 480i/480p. Both HDMI and component overscan were essentially the same.

The black level on the Panasonic, with the iris On, measured a very low 0.003 foot-Lamberts on my 78-inch wide, Stewart Studiotek 130 screen (gain 1.3). The full screen peak contrast ratio measured 4,267:1 (12.8fL peak white/0.003fL video black). Because of the potential errors involved in reading a level of 0.003fL (our Minolta light meter is rated down to 0.001fL, but only reads to three decimal places) I took another reading, this time on an image less than 18" wide using a sample of the same screen material. This increased both the black and white levels by a factor of nearly 20, making them far easier to read them with accuracy. By this technique, the peak contrast measured 3892:1. I also took a modified ANSI contrast ratio measurement with this same close-reading technique and obtained a value of 223:1.

(This small screen, modified ANSI measurement was taken on just the four center black and white squares in the standard 16 square checkerboard pattern. As much as possible, I covered up out all but the specific square being measured (with black cloth) to limit room reflections. This was far easier to do on a small screen area, since none of the squares measured more than roughly 16 square inches. When I measured the two black squares, therefore, none of the white squares were reflecting full screen illumination into my completely dark but less than completely non-reflective studio.)

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